diff --git a/ClosedXML/ClosedXML/ClosedXML/ClosedXML.csproj b/ClosedXML/ClosedXML/ClosedXML/ClosedXML.csproj
index 788695a..e61a62f 100644
--- a/ClosedXML/ClosedXML/ClosedXML/ClosedXML.csproj
+++ b/ClosedXML/ClosedXML/ClosedXML/ClosedXML.csproj
@@ -231,6 +231,7 @@
     <Compile Include="Excel\XLWorksheetInternals.cs" />
     <Compile Include="Excel\XLWorkbookProperties.cs" />
     <Compile Include="Excel\XLWorksheets.cs" />
+    <Compile Include="Excel\XLWSContentManager.cs" />
     <Compile Include="Extensions.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
   </ItemGroup>
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/IXLCell.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/IXLCell.cs
index 71815b3..f20106a 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/IXLCell.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/IXLCell.cs
@@ -146,5 +146,28 @@
         IXLCells InsertCellsBelow(int numberOfRows);
         IXLCells InsertCellsAfter(int numberOfColumns);
         IXLCells InsertCellsBefore(int numberOfColumns);
+
+        /// <summary>
+        /// Creates a named range out of this cell. 
+        /// <para>If the named range exists, it will add this range to that named range.</para>
+        /// <para>The default scope for the named range is Workbook.</para>
+        /// </summary>
+        /// <param name="rangeName">Name of the range.</param>
+        IXLCell AddToNamed(String rangeName);
+
+        /// <summary>
+        /// Creates a named range out of this cell. 
+        /// <para>If the named range exists, it will add this range to that named range.</para>
+        /// <param name="rangeName">Name of the range.</param>
+        /// <param name="scope">The scope for the named range.</param>
+        IXLCell AddToNamed(String rangeName, XLScope scope);
+
+        /// <summary>
+        /// Creates a named range out of this cell. 
+        /// <para>If the named range exists, it will add this range to that named range.</para>
+        /// <param name="rangeName">Name of the range.</param>
+        /// <param name="scope">The scope for the named range.</param>
+        /// <param name="comment">The comments for the named range.</param>
+        IXLCell AddToNamed(String rangeName, XLScope scope, String comment);
     }
 }
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCell.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCell.cs
index cc4ed87..fb027fc 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCell.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCell.cs
@@ -288,7 +288,9 @@
                     maxRows = lastCellUsed.Address.RowNumber;
                     maxColumns = lastCellUsed.Address.ColumnNumber;
                     //if (asRange is XLRow)
+                    //{
                     //    worksheet.Range(Address.RowNumber, Address.ColumnNumber,  , maxColumns).Clear();
+                    //}
                 }
                 else
                 {
@@ -1127,6 +1129,7 @@
         //        FormulaA1 = GetFormula(formulaR1C1, FormulaConversionType.R1C1toA1, rowsToShift, columnsToShift);
         //}
 
+
         internal void ShiftFormulaRows(XLRange shiftedRange, int rowsShifted)
         {
             if (!StringExtensions.IsNullOrWhiteSpace(FormulaA1))
@@ -1491,5 +1494,22 @@
         {
             return this.AsRange().InsertColumnsBefore(numberOfColumns).Cells();
         }
+
+
+        public IXLCell AddToNamed(String rangeName)
+        {
+            this.AsRange().AddToNamed(rangeName);
+            return this;
+        }
+        public IXLCell AddToNamed(String rangeName, XLScope scope)
+        {
+            this.AsRange().AddToNamed(rangeName, scope);
+            return this;
+        }
+        public IXLCell AddToNamed(String rangeName, XLScope scope, String comment)
+        {
+            this.AsRange().AddToNamed(rangeName, scope, comment);
+            return this;
+        }
     }
 }
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/DataValidation/XLDataValidation.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/DataValidation/XLDataValidation.cs
index 15b4865..8166472 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/DataValidation/XLDataValidation.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/DataValidation/XLDataValidation.cs
@@ -16,6 +16,7 @@
             ShowErrorMessage = true;
             ShowInputMessage = true;
             InCellDropdown = true;
+            Operator = XLOperator.Between;
             this.worksheet = worksheet;
         }
         public IXLRanges Ranges { get; set; }
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeBase.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeBase.cs
index b251ff1..c3b3b7a 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeBase.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeBase.cs
@@ -799,7 +799,7 @@
         }
         public IXLRange AddToNamed(String rangeName, XLScope scope)
         {
-            return AddToNamed(rangeName, XLScope.Workbook, null);
+            return AddToNamed(rangeName, scope, null);
         }
         public IXLRange AddToNamed(String rangeName, XLScope scope, String comment)
         {
@@ -955,6 +955,7 @@
                 }
                 else
                 {
+                    List<IXLDataValidation> dvEmpty = new List<IXLDataValidation>();
                     foreach (var dv in Worksheet.DataValidations)
                     {
                         foreach (var dvRange in dv.Ranges)
@@ -967,10 +968,14 @@
                                     if (!this.Contains(c.Address.ToString()))
                                         dv.Ranges.Add(c.AsRange());
                                 }
+                                if (dv.Ranges.Count() == 0)
+                                    dvEmpty.Add(dv);
                             }
                         }
                     }
 
+                    dvEmpty.ForEach(dv => (Worksheet.DataValidations as XLDataValidations).Delete(dv));
+
                     var newRanges = new XLRanges(Worksheet.Internals.Workbook, Style);
                     newRanges.Add(this.AsRange());
                     var dataValidation = new XLDataValidation(newRanges, Worksheet);
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWSContentManager.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWSContentManager.cs
new file mode 100644
index 0000000..5b75803
--- /dev/null
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWSContentManager.cs
@@ -0,0 +1,112 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using DocumentFormat.OpenXml;
+using DocumentFormat.OpenXml.Spreadsheet;
+
+namespace ClosedXML.Excel
+{
+    internal class XLWSContentManager
+    {
+        public enum XLWSContents
+        {
+            SheetProperties = 1,
+            SheetDimension = 2,
+            SheetViews = 3,
+            SheetFormatProperties = 4,
+            Columns = 5,
+            SheetData = 6,
+            SheetCalculationProperties = 7,
+            SheetProtection = 8,
+            ProtectedRanges = 9,
+            Scenarios = 10,
+            AutoFilter = 11,
+            SortState = 12,
+            DataConsolidate = 13,
+            CustomSheetViews = 14,
+            MergeCells = 15,
+            PhoneticProperties = 16,
+            ConditionalFormatting = 17,
+            DataValidations = 18,
+            Hyperlinks = 19,
+            PrintOptions = 20,
+            PageMargins = 21,
+            PageSetup = 22,
+            HeaderFooter = 23,
+            RowBreaks = 24,
+            ColumnBreaks = 25,
+            CustomProperties = 26,
+            CellWatches = 27,
+            IgnoredErrors = 28,
+            SmartTags = 29,
+            Drawing = 30,
+            LegacyDrawing = 31,
+            LegacyDrawingHeaderFooter = 32,
+            DrawingHeaderFooter = 33,
+            Picture = 34,
+            OleObjects = 35,
+            Controls = 36,
+            AlternateContent = 37,
+            WebPublishItems = 38,
+            TableParts = 39,
+            WorksheetExtensionList = 40
+        }
+        private Dictionary<XLWSContents, OpenXmlElement> contents = new Dictionary<XLWSContents, OpenXmlElement>();
+
+        public XLWSContentManager(Worksheet opWorksheet)
+        {
+            contents.Add(XLWSContents.SheetProperties, opWorksheet.Elements<SheetProperties>().FirstOrDefault());
+            contents.Add(XLWSContents.SheetDimension, opWorksheet.Elements<SheetDimension>().FirstOrDefault());
+            contents.Add(XLWSContents.SheetViews, opWorksheet.Elements<SheetViews>().FirstOrDefault());
+            contents.Add(XLWSContents.SheetFormatProperties, opWorksheet.Elements<SheetFormatProperties>().FirstOrDefault());
+            contents.Add(XLWSContents.Columns, opWorksheet.Elements<Columns>().FirstOrDefault());
+            contents.Add(XLWSContents.SheetData, opWorksheet.Elements<SheetData>().FirstOrDefault());
+            contents.Add(XLWSContents.SheetCalculationProperties, opWorksheet.Elements<SheetCalculationProperties>().FirstOrDefault());
+            contents.Add(XLWSContents.SheetProtection, opWorksheet.Elements<SheetProtection>().FirstOrDefault());
+            contents.Add(XLWSContents.ProtectedRanges, opWorksheet.Elements<ProtectedRanges>().FirstOrDefault());
+            contents.Add(XLWSContents.Scenarios, opWorksheet.Elements<Scenarios>().FirstOrDefault());
+            contents.Add(XLWSContents.AutoFilter, opWorksheet.Elements<AutoFilter>().FirstOrDefault());
+            contents.Add(XLWSContents.SortState, opWorksheet.Elements<SortState>().FirstOrDefault());
+            contents.Add(XLWSContents.DataConsolidate, opWorksheet.Elements<DataConsolidate>().FirstOrDefault());
+            contents.Add(XLWSContents.CustomSheetViews, opWorksheet.Elements<CustomSheetViews>().FirstOrDefault());
+            contents.Add(XLWSContents.MergeCells, opWorksheet.Elements<MergeCells>().FirstOrDefault());
+            contents.Add(XLWSContents.PhoneticProperties, opWorksheet.Elements<PhoneticProperties>().FirstOrDefault());
+            contents.Add(XLWSContents.ConditionalFormatting, opWorksheet.Elements<ConditionalFormatting>().FirstOrDefault());
+            contents.Add(XLWSContents.DataValidations, opWorksheet.Elements<DataValidations>().FirstOrDefault());
+            contents.Add(XLWSContents.Hyperlinks, opWorksheet.Elements<Hyperlinks>().FirstOrDefault());
+            contents.Add(XLWSContents.PrintOptions, opWorksheet.Elements<PrintOptions>().FirstOrDefault());
+            contents.Add(XLWSContents.PageMargins, opWorksheet.Elements<PageMargins>().FirstOrDefault());
+            contents.Add(XLWSContents.PageSetup, opWorksheet.Elements<PageSetup>().FirstOrDefault());
+            contents.Add(XLWSContents.HeaderFooter, opWorksheet.Elements<HeaderFooter>().FirstOrDefault());
+            contents.Add(XLWSContents.RowBreaks, opWorksheet.Elements<RowBreaks>().FirstOrDefault());
+            contents.Add(XLWSContents.ColumnBreaks, opWorksheet.Elements<ColumnBreaks>().FirstOrDefault());
+            contents.Add(XLWSContents.CustomProperties, opWorksheet.Elements<CustomProperties>().FirstOrDefault());
+            contents.Add(XLWSContents.CellWatches, opWorksheet.Elements<CellWatches>().FirstOrDefault());
+            contents.Add(XLWSContents.IgnoredErrors, opWorksheet.Elements<IgnoredErrors>().FirstOrDefault());
+            contents.Add(XLWSContents.SmartTags, opWorksheet.Elements<SmartTags>().FirstOrDefault());
+            contents.Add(XLWSContents.Drawing, opWorksheet.Elements<Drawing>().FirstOrDefault());
+            contents.Add(XLWSContents.LegacyDrawing, opWorksheet.Elements<LegacyDrawing>().FirstOrDefault());
+            contents.Add(XLWSContents.LegacyDrawingHeaderFooter, opWorksheet.Elements<LegacyDrawingHeaderFooter>().FirstOrDefault());
+            contents.Add(XLWSContents.DrawingHeaderFooter, opWorksheet.Elements<DrawingHeaderFooter>().FirstOrDefault());
+            contents.Add(XLWSContents.Picture, opWorksheet.Elements<Picture>().FirstOrDefault());
+            contents.Add(XLWSContents.OleObjects, opWorksheet.Elements<OleObjects>().FirstOrDefault());
+            contents.Add(XLWSContents.Controls, opWorksheet.Elements<Controls>().FirstOrDefault());
+            contents.Add(XLWSContents.AlternateContent, opWorksheet.Elements<AlternateContent>().FirstOrDefault());
+            contents.Add(XLWSContents.WebPublishItems, opWorksheet.Elements<WebPublishItems>().FirstOrDefault());
+            contents.Add(XLWSContents.TableParts, opWorksheet.Elements<TableParts>().FirstOrDefault());
+            contents.Add(XLWSContents.WorksheetExtensionList, opWorksheet.Elements<WorksheetExtensionList>().FirstOrDefault());
+        }
+
+        public void SetElement(XLWSContents content, OpenXmlElement element)
+        {
+            contents[content] = element;
+        }
+
+        public OpenXmlElement GetPreviousElementFor(XLWSContents content)
+        {
+            var max = contents.Where(kp => (Int32)kp.Key < (Int32)content && kp.Value != null).Max(kp => kp.Key);
+            return contents[max];
+        }
+    }
+}
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Load.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Load.cs
index 6f06459..3c1b64c 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Load.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Load.cs
@@ -309,24 +309,39 @@
                         else
                             xlCell.Style.NumberFormat.NumberFormatId = Int32.Parse(numberFormatId);
 
-                        if (val >= 0 && val <= DateTimeExtensions.MaxOADate)
-                        {
-                            String format = xlCell.Style.NumberFormat.Format.EndsWith(";@") ? xlCell.Style.NumberFormat.Format.Substring(0, xlCell.Style.NumberFormat.Format.Length - 2) : xlCell.Style.NumberFormat.Format;
 
-                            Double dTest;
-                            if (!Double.TryParse(val.ToString(format), out dTest))
+                        if (!StringExtensions.IsNullOrWhiteSpace(xlCell.Style.NumberFormat.Format))
+                            xlCell.DataType = GetDataTypeFromFormat(xlCell.Style.NumberFormat.Format);
+                        else
+                            if ((numberFormatId >= 14 && numberFormatId <= 22) || (numberFormatId >= 45 && numberFormatId <= 47))
                                 xlCell.DataType = XLCellValues.DateTime;
+                            else if (numberFormatId == 0 || numberFormatId == 49)
+                                xlCell.DataType = XLCellValues.Text;
+                            else
+                                xlCell.DataType = XLCellValues.Number;
+                                
 
-                            ////String format = xlCell.Style.NumberFormat.Format.EndsWith(";@") ? xlCell.Style.NumberFormat.Format.Substring(0, xlCell.Style.NumberFormat.Format.Length - 2) : xlCell.Style.NumberFormat.Format;
-                            
-                            ////Double dTest;
-                            ////if (!Double.TryParse(val.ToString(format) , out dTest))
-                            ////DateTime dTest;
-                            ////if (DateTime.TryParseExact(DateTime.FromOADate(val).ToString(format), format, CultureInfo.InvariantCulture, DateTimeStyles.None , out dTest))
-                            ////if (DateTime.TryParse(val.ToString(format), out dTest))
-                            //if ((numberFormatId >= 14 && numberFormatId <= 22) || (numberFormatId >= 165 && numberFormatId <= 180))
-                            //    xlCell.DataType = XLCellValues.DateTime;
-                        }
+                        //if (val >= 0 && val <= DateTimeExtensions.MaxOADate)
+                        //{
+                        //    xlCell.DataType = GetDataTypeFromFormat(xlCell.Style.NumberFormat.Format);
+                        //    //String format = xlCell.Style.NumberFormat.Format.EndsWith(";@") ? xlCell.Style.NumberFormat.Format.Substring(0, xlCell.Style.NumberFormat.Format.Length - 2) : xlCell.Style.NumberFormat.Format;
+
+                        //    //Double dTest;
+                        //    //if (!Double.TryParse(val.ToString(format), out dTest))
+                        //    //    xlCell.DataType = XLCellValues.DateTime;
+
+                        //    //String format = xlCell.Style.NumberFormat.Format.EndsWith(";@") ? xlCell.Style.NumberFormat.Format.Substring(0, xlCell.Style.NumberFormat.Format.Length - 2) : xlCell.Style.NumberFormat.Format;
+                        //    //format = FixFormatForDates(format);
+                        //    ////Double dTest;
+                        //    ////if (!Double.TryParse(val.ToString(format) , out dTest))
+                        //    //DateTime dTest;
+                        //    //if (DateTime.TryParseExact(DateTime.FromOADate(val).ToString(format), format, CultureInfo.InvariantCulture, DateTimeStyles.None , out dTest))
+                        //    //    xlCell.DataType = XLCellValues.DateTime;
+
+                        //    ////if (DateTime.TryParse(val.ToString(format), out dTest))
+                        //    //if ((numberFormatId >= 14 && numberFormatId <= 22) || (numberFormatId >= 165 && numberFormatId <= 180))
+                        //    //    xlCell.DataType = XLCellValues.DateTime;
+                        //}
                     }
                 }
                 #endregion
@@ -443,6 +458,23 @@
             }
         }
 
+        private XLCellValues GetDataTypeFromFormat(String format)
+        {
+            var length = format.Length;
+            String f = format.ToLower();
+            for (Int32 i = 0; i < length; i++)
+            {
+                Char c = f[i];
+                if (c == '"')
+                    i = f.IndexOf('"', i + 1);
+                else if (c == '0' || c == '#' || c == '?')
+                    return XLCellValues.Number;
+                else if (c == 'y' || c == 'm' || c == 'd' || c == 'h' || c == 's')
+                    return XLCellValues.DateTime;
+            }
+            return XLCellValues.Text;
+        }
+
         private void LoadDataValidations(WorksheetPart worksheetPart, XLWorksheet ws)
         {
             var dataValidationList = worksheetPart.Worksheet.Descendants<DataValidations>();
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Save.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Save.cs
index 793a197..44ddc38 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Save.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Save.cs
@@ -738,7 +738,7 @@
                     if (!StringExtensions.IsNullOrWhiteSpace(nr.Comment)) definedName.Comment = nr.Comment;
                     definedNames.Append(definedName);
                 }
-
+                
                 var titles = String.Empty;
                 var definedNameTextRow = String.Empty;
                 var definedNameTextColumn = String.Empty;
@@ -1510,6 +1510,7 @@
         #region GenerateWorksheetPartContent
         private void GenerateWorksheetPartContent(WorksheetPart worksheetPart, XLWorksheet xlWorksheet)
         {
+            
             #region Worksheet
             if (worksheetPart.Worksheet == null)
                 worksheetPart.Worksheet = new Worksheet();
@@ -1520,10 +1521,14 @@
                 worksheetPart.Worksheet.AddNamespaceDeclaration("r", "http://schemas.openxmlformats.org/officeDocument/2006/relationships");
             #endregion
 
+            var cm = new XLWSContentManager(worksheetPart.Worksheet);
+
             #region SheetProperties
             if (worksheetPart.Worksheet.SheetProperties == null)
                 worksheetPart.Worksheet.SheetProperties = new SheetProperties() { CodeName = xlWorksheet.Name.RemoveSpecialCharacters() };
 
+            cm.SetElement(XLWSContentManager.XLWSContents.SheetProperties, worksheetPart.Worksheet.SheetProperties);
+
             if (worksheetPart.Worksheet.SheetProperties.OutlineProperties == null)
                 worksheetPart.Worksheet.SheetProperties.OutlineProperties = new OutlineProperties();
 
@@ -1566,9 +1571,13 @@
             if (worksheetPart.Worksheet.SheetDimension == null)
                 worksheetPart.Worksheet.SheetDimension = new SheetDimension() { Reference = sheetDimensionReference };
 
+            cm.SetElement(XLWSContentManager.XLWSContents.SheetDimension, worksheetPart.Worksheet.SheetDimension);
+
             if (worksheetPart.Worksheet.SheetViews == null)
                 worksheetPart.Worksheet.SheetViews = new SheetViews();
 
+            cm.SetElement(XLWSContentManager.XLWSContents.SheetViews, worksheetPart.Worksheet.SheetViews);
+
             var sheetView = worksheetPart.Worksheet.SheetViews.FirstOrDefault();
             if (worksheetPart.Worksheet.SheetViews.Count() == 0)
             {
@@ -1628,6 +1637,8 @@
             if (worksheetPart.Worksheet.SheetFormatProperties == null)
                 worksheetPart.Worksheet.SheetFormatProperties = new SheetFormatProperties();
 
+            cm.SetElement(XLWSContentManager.XLWSContents.SheetFormatProperties, worksheetPart.Worksheet.SheetFormatProperties);
+
             worksheetPart.Worksheet.SheetFormatProperties.DefaultRowHeight = xlWorksheet.RowHeight;
             worksheetPart.Worksheet.SheetFormatProperties.DefaultColumnWidth = xlWorksheet.ColumnWidth;
             //worksheetPart.Worksheet.SheetFormatProperties.CustomHeight = true;
@@ -1654,9 +1665,13 @@
                 var worksheetColumnWidth = GetColumnWidth(xlWorksheet.ColumnWidth);
 
                 if (worksheetPart.Worksheet.Elements<Columns>().Count() == 0)
-                    worksheetPart.Worksheet.InsertAfter(new Columns(), worksheetPart.Worksheet.SheetFormatProperties);
+                {
+                    var previousElement = cm.GetPreviousElementFor(XLWSContentManager.XLWSContents.Columns);
+                    worksheetPart.Worksheet.InsertAfter(new Columns(), previousElement);
+                }
 
                 columns = worksheetPart.Worksheet.Elements<Columns>().First();
+                cm.SetElement(XLWSContentManager.XLWSContents.Columns, columns);
 
                 Dictionary<UInt32, Column> sheetColumnsByMin = columns.Elements<Column>().ToDictionary(c => c.Min.Value, c => c);
                 //Dictionary<UInt32, Column> sheetColumnsByMax = columns.Elements<Column>().ToDictionary(c => c.Max.Value, c => c);
@@ -1761,15 +1776,12 @@
             SheetData sheetData;
             if (worksheetPart.Worksheet.Elements<SheetData>().Count() == 0)
             {
-                OpenXmlElement previousElement;
-                if (columns != null)
-                    previousElement = columns;
-                else
-                    previousElement = worksheetPart.Worksheet.SheetFormatProperties;
+                OpenXmlElement previousElement = cm.GetPreviousElementFor(XLWSContentManager.XLWSContents.SheetData);
                 worksheetPart.Worksheet.InsertAfter(new SheetData(), previousElement);
             }
 
             sheetData = worksheetPart.Worksheet.Elements<SheetData>().First();
+            cm.SetElement(XLWSContentManager.XLWSContents.SheetData, sheetData);
 
             var cellsByRow = new Dictionary<Int32, List<IXLCell>>();
             foreach (var c in xlWorksheet.Internals.CellsCollection.Values)
@@ -1969,32 +1981,18 @@
             }
             #endregion
 
-            var autoFilter = worksheetPart.Worksheet.Elements<AutoFilter>().FirstOrDefault();
-
-            CustomSheetViews customSheetViews = worksheetPart.Worksheet.Elements<CustomSheetViews>().FirstOrDefault();
-
             #region MergeCells
             MergeCells mergeCells = null;
             if (xlWorksheet.Internals.MergedRanges.Count() > 0)
             {
                 if (worksheetPart.Worksheet.Elements<MergeCells>().Count() == 0)
                 {
-                    OpenXmlElement previousElement;
-                    if (customSheetViews != null)
-                        previousElement = customSheetViews;
-                    else if (autoFilter != null)
-                        previousElement = autoFilter;
-                    else if (sheetData != null)
-                        previousElement = sheetData;
-                    else if (columns != null)
-                        previousElement = columns;
-                    else
-                        previousElement = worksheetPart.Worksheet.SheetFormatProperties;
-
+                    OpenXmlElement previousElement = cm.GetPreviousElementFor(XLWSContentManager.XLWSContents.MergeCells);
                     worksheetPart.Worksheet.InsertAfter(new MergeCells(), previousElement);
                 }
 
                 mergeCells = worksheetPart.Worksheet.Elements<MergeCells>().First();
+                cm.SetElement(XLWSContentManager.XLWSContents.MergeCells, mergeCells);
                 mergeCells.RemoveAllChildren<MergeCell>();
 
                 foreach (var merged in xlWorksheet.Internals.MergedRanges.Select(m => m.RangeAddress.FirstAddress.ToString() + ":" + m.RangeAddress.LastAddress.ToString()))
@@ -2011,10 +2009,6 @@
             }
             #endregion
 
-            var phoneticProperties = worksheetPart.Worksheet.Elements<PhoneticProperties>().FirstOrDefault();
-            
-            var conditionalFormatting = worksheetPart.Worksheet.Elements<ConditionalFormatting>().LastOrDefault();
-
             #region DataValidations
             DataValidations dataValidations = null;
             
@@ -2027,28 +2021,12 @@
                 worksheetPart.Worksheet.Elements<DataValidations>().FirstOrDefault();
                 if (worksheetPart.Worksheet.Elements<DataValidations>().Count() == 0)
                 {
-                    OpenXmlElement previousElement;
-                    if (conditionalFormatting != null)
-                        previousElement = conditionalFormatting;
-                    else if (phoneticProperties != null)
-                        previousElement = phoneticProperties;
-                    else if (mergeCells != null)
-                        previousElement = mergeCells;
-                    else if (customSheetViews != null)
-                        previousElement = customSheetViews;
-                    else if (autoFilter != null)
-                        previousElement = autoFilter;
-                    else if (sheetData != null)
-                        previousElement = sheetData;
-                    else if (columns != null)
-                        previousElement = columns;
-                    else
-                        previousElement = worksheetPart.Worksheet.SheetFormatProperties;
-
+                    OpenXmlElement previousElement = cm.GetPreviousElementFor(XLWSContentManager.XLWSContents.DataValidations);
                     worksheetPart.Worksheet.InsertAfter(new DataValidations(), previousElement);
                 }
 
                 dataValidations = worksheetPart.Worksheet.Elements<DataValidations>().First();
+                cm.SetElement(XLWSContentManager.XLWSContents.DataValidations, dataValidations);
                 dataValidations.RemoveAllChildren<DataValidation>();
                 foreach (var dv in xlWorksheet.DataValidations)
                 {
@@ -2100,30 +2078,12 @@
                 worksheetPart.Worksheet.Elements<Hyperlinks>().FirstOrDefault();
                 if (worksheetPart.Worksheet.Elements<Hyperlinks>().Count() == 0)
                 {
-                    OpenXmlElement previousElement;
-                    if (dataValidations != null)
-                        previousElement = dataValidations;
-                    else if (conditionalFormatting != null)
-                        previousElement = conditionalFormatting;
-                    else if (phoneticProperties != null)
-                        previousElement = phoneticProperties;
-                    else if (mergeCells != null)
-                        previousElement = mergeCells;
-                    else if (customSheetViews != null)
-                        previousElement = customSheetViews;
-                    else if (autoFilter != null)
-                        previousElement = autoFilter;
-                    else if (sheetData != null)
-                        previousElement = sheetData;
-                    else if (columns != null)
-                        previousElement = columns;
-                    else
-                        previousElement = worksheetPart.Worksheet.SheetFormatProperties;
-
+                    OpenXmlElement previousElement = cm.GetPreviousElementFor(XLWSContentManager.XLWSContents.Hyperlinks);
                     worksheetPart.Worksheet.InsertAfter(new Hyperlinks(), previousElement);
                 }
 
                 hyperlinks = worksheetPart.Worksheet.Elements<Hyperlinks>().First();
+                cm.SetElement(XLWSContentManager.XLWSContents.Hyperlinks, hyperlinks);
                 hyperlinks.RemoveAllChildren<Hyperlink>();
                 foreach (var hl in xlWorksheet.Hyperlinks)
                 {
@@ -2154,32 +2114,12 @@
             PrintOptions printOptions = null;
             if (worksheetPart.Worksheet.Elements<PrintOptions>().Count() == 0)
             {
-                OpenXmlElement previousElement;
-                if (hyperlinks != null)
-                    previousElement = hyperlinks;
-                else if (dataValidations != null)
-                    previousElement = dataValidations;
-                else if (conditionalFormatting != null)
-                    previousElement = conditionalFormatting;
-                else if (phoneticProperties != null)
-                    previousElement = phoneticProperties;
-                else if (mergeCells != null)
-                    previousElement = mergeCells;
-                else if (customSheetViews != null)
-                    previousElement = customSheetViews;
-                else if (autoFilter != null)
-                    previousElement = autoFilter;
-                else if (sheetData != null)
-                    previousElement = sheetData;
-                else if (columns != null)
-                    previousElement = columns;
-                else
-                    previousElement = worksheetPart.Worksheet.SheetFormatProperties;
-
+                OpenXmlElement previousElement = cm.GetPreviousElementFor(XLWSContentManager.XLWSContents.PrintOptions);
                 worksheetPart.Worksheet.InsertAfter(new PrintOptions(), previousElement);
             }
 
             printOptions = worksheetPart.Worksheet.Elements<PrintOptions>().First();
+            cm.SetElement(XLWSContentManager.XLWSContents.PrintOptions, printOptions);
 
             printOptions.HorizontalCentered = xlWorksheet.PageSetup.CenterHorizontally;
             printOptions.VerticalCentered = xlWorksheet.PageSetup.CenterVertically;
@@ -2190,34 +2130,12 @@
             #region PageMargins
             if (worksheetPart.Worksheet.Elements<PageMargins>().Count() == 0)
             {
-                OpenXmlElement previousElement;
-                if (printOptions != null)
-                    previousElement = printOptions;
-                else if (hyperlinks != null)
-                    previousElement = hyperlinks;
-                else if (dataValidations != null)
-                    previousElement = dataValidations;
-                else if (conditionalFormatting != null)
-                    previousElement = conditionalFormatting;
-                else if (phoneticProperties != null)
-                    previousElement = phoneticProperties;
-                else if (mergeCells != null)
-                    previousElement = mergeCells;
-                else if (customSheetViews != null)
-                    previousElement = customSheetViews;
-                else if (autoFilter != null)
-                    previousElement = autoFilter;
-                else if (sheetData != null)
-                    previousElement = sheetData;
-                else if (columns != null)
-                    previousElement = columns;
-                else
-                    previousElement = worksheetPart.Worksheet.SheetFormatProperties;
-
+                OpenXmlElement previousElement = cm.GetPreviousElementFor(XLWSContentManager.XLWSContents.PageMargins);
                 worksheetPart.Worksheet.InsertAfter(new PageMargins(), previousElement);
             }
 
             PageMargins pageMargins = worksheetPart.Worksheet.Elements<PageMargins>().First();
+            cm.SetElement(XLWSContentManager.XLWSContents.PageMargins, pageMargins);
             pageMargins.Left = xlWorksheet.PageSetup.Margins.Left;
             pageMargins.Right = xlWorksheet.PageSetup.Margins.Right;
             pageMargins.Top = xlWorksheet.PageSetup.Margins.Top;
@@ -2229,10 +2147,12 @@
             #region PageSetup
             if (worksheetPart.Worksheet.Elements<PageSetup>().Count() == 0)
             {
-                worksheetPart.Worksheet.InsertAfter(new PageSetup(), pageMargins);
+                var previousElement = cm.GetPreviousElementFor(XLWSContentManager.XLWSContents.PageSetup);
+                worksheetPart.Worksheet.InsertAfter(new PageSetup(), previousElement);
             }
 
             PageSetup pageSetup = worksheetPart.Worksheet.Elements<PageSetup>().First();
+            cm.SetElement(XLWSContentManager.XLWSContents.PageSetup, pageSetup);
 
             pageSetup.Orientation = pageOrientationValues.Single(p => p.Key == xlWorksheet.PageSetup.PageOrientation).Value;
             pageSetup.PaperSize = (UInt32)xlWorksheet.PageSetup.PaperSize;
@@ -2287,9 +2207,13 @@
 
             #region HeaderFooter
             if (worksheetPart.Worksheet.Elements<HeaderFooter>().Count() == 0)
-                worksheetPart.Worksheet.InsertAfter(new HeaderFooter(), pageSetup);
+            {
+                var previousElement = cm.GetPreviousElementFor(XLWSContentManager.XLWSContents.HeaderFooter);
+                worksheetPart.Worksheet.InsertAfter(new HeaderFooter(), previousElement);
+            }
 
             HeaderFooter headerFooter = worksheetPart.Worksheet.Elements<HeaderFooter>().First();
+            cm.SetElement(XLWSContentManager.XLWSContents.HeaderFooter, headerFooter);
             headerFooter.RemoveAllChildren();
 
             headerFooter.ScaleWithDoc = xlWorksheet.PageSetup.ScaleHFWithDocument;
@@ -2319,17 +2243,12 @@
             #region RowBreaks
             if (worksheetPart.Worksheet.Elements<RowBreaks>().Count() == 0)
             {
-                OpenXmlElement previousElement;
-                if (worksheetPart.Worksheet.Elements<HeaderFooter>().Count() > 0)
-                    previousElement = headerFooter;
-                else
-                    previousElement = pageSetup;
-
+                OpenXmlElement previousElement = cm.GetPreviousElementFor(XLWSContentManager.XLWSContents.RowBreaks);
                 worksheetPart.Worksheet.InsertAfter(new RowBreaks(), previousElement);
             }
 
             RowBreaks rowBreaks = worksheetPart.Worksheet.Elements<RowBreaks>().First();
-
+            
             var rowBreakCount = xlWorksheet.PageSetup.RowBreaks.Count;
             if (rowBreakCount > 0)
             {
@@ -2340,11 +2259,12 @@
                     Break break1 = new Break() { Id = (UInt32)rb, Max = (UInt32)xlWorksheet.RangeAddress.LastAddress.RowNumber, ManualPageBreak = true };
                     rowBreaks.Append(break1);
                 }
-
+                cm.SetElement(XLWSContentManager.XLWSContents.RowBreaks, rowBreaks);
             }
             else
             {
                 worksheetPart.Worksheet.RemoveAllChildren<RowBreaks>();
+                cm.SetElement(XLWSContentManager.XLWSContents.RowBreaks, null);
             }
             #endregion
 
@@ -2352,14 +2272,7 @@
 
             if (worksheetPart.Worksheet.Elements<ColumnBreaks>().Count() == 0)
             {
-                OpenXmlElement previousElement;
-                if (worksheetPart.Worksheet.Elements<RowBreaks>().Count() > 0)
-                    previousElement = rowBreaks;
-                else if (worksheetPart.Worksheet.Elements<HeaderFooter>().Count() > 0)
-                    previousElement = headerFooter;
-                else
-                    previousElement = pageSetup;
-
+                OpenXmlElement previousElement = cm.GetPreviousElementFor(XLWSContentManager.XLWSContents.ColumnBreaks);
                 worksheetPart.Worksheet.InsertAfter(new ColumnBreaks(), previousElement);
             }
 
@@ -2375,51 +2288,24 @@
                     Break break1 = new Break() { Id = (UInt32)cb, Max = (UInt32)xlWorksheet.RangeAddress.LastAddress.ColumnNumber, ManualPageBreak = true };
                     columnBreaks.Append(break1);
                 }
+                cm.SetElement(XLWSContentManager.XLWSContents.ColumnBreaks, columnBreaks);
             }
             else
             {
                 worksheetPart.Worksheet.RemoveAllChildren<ColumnBreaks>();
+                cm.SetElement(XLWSContentManager.XLWSContents.ColumnBreaks, null);
             }
             #endregion
 
-            #region Drawings & OleObjects
-            Drawing drawing = worksheetPart.Worksheet.Elements<Drawing>().FirstOrDefault();
-            LegacyDrawing legacyDrawing = worksheetPart.Worksheet.Elements<LegacyDrawing>().FirstOrDefault();
-            LegacyDrawingHeaderFooter legacyDrawingHF = worksheetPart.Worksheet.Elements<LegacyDrawingHeaderFooter>().FirstOrDefault();
-            OleObjects oleObjects = worksheetPart.Worksheet.Elements<OleObjects>().FirstOrDefault();
-            #endregion
-
-            #region Controls
-            Controls controls = worksheetPart.Worksheet.Elements<Controls>().FirstOrDefault();
-            #endregion
-
             #region Tables
             worksheetPart.Worksheet.RemoveAllChildren<TableParts>();
             {
-                OpenXmlElement previousElement;
-                if (controls != null)
-                    previousElement = controls;
-                else if (oleObjects != null)
-                    previousElement = oleObjects;
-                else if (legacyDrawingHF != null)
-                    previousElement = legacyDrawingHF;
-                else if (legacyDrawing != null)
-                    previousElement = legacyDrawing;
-                else if (drawing != null)
-                    previousElement = drawing;
-                else if (worksheetPart.Worksheet.Elements<ColumnBreaks>().Count() > 0)
-                    previousElement = columnBreaks;
-                else if (worksheetPart.Worksheet.Elements<RowBreaks>().Count() > 0)
-                    previousElement = rowBreaks;
-                else if (worksheetPart.Worksheet.Elements<HeaderFooter>().Count() > 0)
-                    previousElement = headerFooter;
-                else
-                    previousElement = pageSetup;
-
+                OpenXmlElement previousElement = cm.GetPreviousElementFor(XLWSContentManager.XLWSContents.TableParts);
                 worksheetPart.Worksheet.InsertAfter(new TableParts(), previousElement);
             }
 
             TableParts tableParts = worksheetPart.Worksheet.Elements<TableParts>().First();
+            cm.SetElement(XLWSContentManager.XLWSContents.TableParts, tableParts);
 
             tableParts.Count = (UInt32)xlWorksheet.Tables.Count();
             foreach (var table in xlWorksheet.Tables)
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorksheet.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorksheet.cs
index 6fc060d..0acd229 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorksheet.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorksheet.cs
@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
+using System.Text.RegularExpressions;
 
 
 namespace ClosedXML.Excel
@@ -628,5 +629,7 @@
             return this;
         }
 
+
+       
     }
 }
diff --git a/ClosedXML/ClosedXML/ClosedXML_Examples/Misc/InsertingTables.cs b/ClosedXML/ClosedXML/ClosedXML_Examples/Misc/InsertingTables.cs
index 63ec472..963664e 100644
--- a/ClosedXML/ClosedXML/ClosedXML_Examples/Misc/InsertingTables.cs
+++ b/ClosedXML/ClosedXML/ClosedXML_Examples/Misc/InsertingTables.cs
@@ -54,11 +54,6 @@
                          where p.Age >= 21
                          select p;
 
-            //var person = new Person() { Name = "Henry", Age = 45, House = "On 5th Ave." };
-            //foreach (var p in person.GetType().GetProperties())
-            //{
-            //    var ats = p.GetCustomAttributes(true);
-            //}
 
             ws.Cell(7, 6).Value = "From Query";
             ws.Range(7, 6, 7, 8).Merge().AddToNamed("Titles");
diff --git a/ClosedXML/ClosedXML/ClosedXML_Net3.5/ClosedXML_Net3.5.csproj b/ClosedXML/ClosedXML/ClosedXML_Net3.5/ClosedXML_Net3.5.csproj
index 26ae34c..521e332 100644
--- a/ClosedXML/ClosedXML/ClosedXML_Net3.5/ClosedXML_Net3.5.csproj
+++ b/ClosedXML/ClosedXML/ClosedXML_Net3.5/ClosedXML_Net3.5.csproj
@@ -454,6 +454,9 @@
     <Compile Include="..\ClosedXML\Excel\XLWorksheets.cs">
       <Link>Excel\XLWorksheets.cs</Link>
     </Compile>
+    <Compile Include="..\ClosedXML\Excel\XLWSContentManager.cs">
+      <Link>Excel\XLWSContentManager.cs</Link>
+    </Compile>
     <Compile Include="..\ClosedXML\Extensions.cs">
       <Link>Extensions.cs</Link>
     </Compile>
diff --git a/ClosedXML/ClosedXML/ClosedXML_Sandbox/Program.cs b/ClosedXML/ClosedXML/ClosedXML_Sandbox/Program.cs
index b8f84fd..16dbd02 100644
--- a/ClosedXML/ClosedXML/ClosedXML_Sandbox/Program.cs
+++ b/ClosedXML/ClosedXML/ClosedXML_Sandbox/Program.cs
@@ -13,59 +13,52 @@
     class Program
     {
 
-        static void xMain(string[] args)
+        static void Main(string[] args)
         {
-            var fileName = "Issue_6313";
+            //var fileName = "DifferentKinds";
             //var fileName = "Blank";
-            //var fileName = "Sandbox";
-            var wb = new XLWorkbook(String.Format(@"c:\Excel Files\ForTesting\{0}.xlsx", fileName));
-            
-            IXLWorksheet sheet = wb.Worksheets.Add("Query Results");
-            
-            // Add the table to the Excel sheet
-            var table = sheet.Cell(1, 1).InsertTable(new List<StringSplitOptions>());
-            // run autofit on all the columns
-            sheet.Columns().AdjustToContents();
-            // Freeze the top row and the first five columns
-            sheet.SheetView.Freeze(1, 5);
-            // Mark the first row as BOLD
-            table.HeadersRow().Style.Font.Bold = true;
-
+            var fileName = "Sandbox";
+            //var wb = new XLWorkbook(String.Format(@"c:\Excel Files\ForTesting\{0}.xlsx", fileName));
             //var wb = new XLWorkbook();
-            //var ws = wb.Worksheets.Add("Shifting Formulas");
-            //ws.Cell("B2").Value = 5;
-            //ws.Cell("B3").Value = 6;
-            //ws.Cell("C2").Value = 1;
-            //ws.Cell("C3").Value = 2;
-            //ws.Cell("A4").Value = "Sum:";
-            //ws.Range("B4:C4").FormulaR1C1 = "Sum(R[-2]C:R[-1]C)";
-            //ws.Cell("E2").Value = "Avg:";
-            
-            //ws.Cell("F2").FormulaA1 = "Average(B2:C3)";
-            //ws.Ranges("A4,E2").Style
-            //    .Font.SetBold()
-            //    .Fill.SetBackgroundColor(XLColor.CyanProcess);
 
-            //var ws2 = wb.Worksheets.Add("WS2");
-            //ws2.Cell(1, 1).FormulaA1 = "='Shifting Formulas'!B2";
-            //ws2.Cell(1, 2).Value = ws2.Cell(1, 1).Value;
-            //ws2.Cell(2, 1).FormulaA1 = "Average('Shifting Formulas'!$B$2:$C$3)";
-            //ws2.Cell(3, 1).FormulaA1 = "Average('Shifting Formulas'!$B$2:$C3)";
-            //ws2.Cell(4, 1).FormulaA1 = "Average('Shifting Formulas'!$B$2:C3)";
-            //ws2.Cell(5, 1).FormulaA1 = "Average('Shifting Formulas'!$B2:C3)";
-            //ws2.Cell(6, 1).FormulaA1 = "Average('Shifting Formulas'!B2:C3)";
-            //ws2.Cell(7, 1).FormulaA1 = "Average('Shifting Formulas'!B2:C$3)";
-            //ws2.Cell(8, 1).FormulaA1 = "Average('Shifting Formulas'!B2:$C$3)";
-            //ws2.Cell(9, 1).FormulaA1 = "Average('Shifting Formulas'!B$2:$C$3)";
 
-            //var dataGrid = ws.Range("B2:D3");
-            //ws.Row(1).InsertRowsAbove(1);
-            //var newRow = dataGrid.LastRow().InsertRowsAbove(1).First();
-            //newRow.Value = 1;
-            //dataGrid.LastColumn().FormulaR1C1 = String.Format("SUM(RC[-{0}]:RC[-1])", dataGrid.ColumnCount() - 1);
-            //ws.Cell(1, 1).InsertCellsBelow(1);
-            //ws.Column(1).InsertColumnsBefore(1);
-            //ws.Row(4).Delete();
+            var wb = new XLWorkbook();
+            var ws = wb.Worksheets.Add("Shifting Formulas");
+            ws.Cell("B2").Value = 5;
+            ws.Cell("B3").Value = 6;
+            ws.Cell("C2").Value = 1;
+            ws.Cell("C3").Value = 2;
+            ws.Cell("A4").Value = "Sum:";
+            ws.Range("B4:C4").FormulaR1C1 = "Sum(R[-2]C:R[-1]C)";
+            ws.Range("B4:C4").AddToNamed("WorkbookB4C4");
+            ws.Range("B4:C4").AddToNamed("WorksheetB4C4", XLScope.Worksheet);
+            ws.Cell("E2").Value = "Avg:";
+
+            ws.Cell("F2").FormulaA1 = "Average(B2:C3)";
+            ws.Ranges("A4,E2").Style
+                .Font.SetBold()
+                .Fill.SetBackgroundColor(XLColor.CyanProcess);
+
+            var ws2 = wb.Worksheets.Add("WS2");
+            ws2.Cell(1, 1).FormulaA1 = "='Shifting Formulas'!B2";
+            ws2.Cell(1, 2).Value = ws2.Cell(1, 1).Value;
+            ws2.Cell(2, 1).FormulaA1 = "Average('Shifting Formulas'!$B$2:$C$3)";
+            ws2.Cell(3, 1).FormulaA1 = "Average('Shifting Formulas'!$B$2:$C3)";
+            ws2.Cell(4, 1).FormulaA1 = "Average('Shifting Formulas'!$B$2:C3)";
+            ws2.Cell(5, 1).FormulaA1 = "Average('Shifting Formulas'!$B2:C3)";
+            ws2.Cell(6, 1).FormulaA1 = "Average('Shifting Formulas'!B2:C3)";
+            ws2.Cell(7, 1).FormulaA1 = "Average('Shifting Formulas'!B2:C$3)";
+            ws2.Cell(8, 1).FormulaA1 = "Average('Shifting Formulas'!B2:$C$3)";
+            ws2.Cell(9, 1).FormulaA1 = "Average('Shifting Formulas'!B$2:$C$3)";
+
+            var dataGrid = ws.Range("B2:D3");
+            ws.Row(1).InsertRowsAbove(1);
+            var newRow = dataGrid.LastRow().InsertRowsAbove(1).First();
+            newRow.Value = 1;
+            dataGrid.LastColumn().FormulaR1C1 = String.Format("SUM(RC[-{0}]:RC[-1])", dataGrid.ColumnCount() - 1);
+            ws.Cell(1, 1).InsertCellsBelow(1);
+            ws.Column(1).InsertColumnsBefore(1);
+            ws.Row(4).Delete();
 
             wb.SaveAs(String.Format(@"c:\Excel Files\ForTesting\{0}_Saved.xlsx", fileName));
         }
@@ -130,7 +123,7 @@
             wb.Save();
         }
 
-        static void Main(string[] args)
+        static void xMain(string[] args)
         {
             FillStyles();
             List<Double> runningSave = new List<Double>();