diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook.cs
index 9379676..f038660 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook.cs
@@ -163,7 +163,7 @@
 
         #endregion
 
-        private readonly Dictionary<Int32, UnsupportedSheet> _unsupportedSheets =
+        internal readonly Dictionary<Int32, UnsupportedSheet> UnsupportedSheets =
             new Dictionary<int, UnsupportedSheet>();
 
         private readonly Dictionary<Int32, IXLStyle> _stylesById = new Dictionary<int, IXLStyle>();
@@ -567,7 +567,7 @@
 
         #region Nested type: UnsupportedSheet
 
-        private sealed class UnsupportedSheet
+        internal sealed class UnsupportedSheet
         {
             public Boolean IsActive;
             public UInt32 SheetId;
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Load.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Load.cs
index 010deab..762189c 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Load.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Load.cs
@@ -117,13 +117,13 @@
 
                 if (wsPart == null)
                 {
-                    _unsupportedSheets.Add(position, new UnsupportedSheet {SheetId = dSheet.SheetId.Value});
+                    UnsupportedSheets.Add(position, new UnsupportedSheet {SheetId = dSheet.SheetId.Value});
                     continue;
                 }
 
                 var sheetName = dSheet.Name;
 
-                var ws = (XLWorksheet) WorksheetsInternal.Add(sheetName);
+                var ws = (XLWorksheet) WorksheetsInternal.Add(sheetName, position);
                 ws.RelId = dSheet.Id;
                 ws.SheetId = (Int32) dSheet.SheetId.Value;
 
@@ -318,10 +318,14 @@
             if (workbookView != null && workbookView.ActiveTab != null)
             {
                 UnsupportedSheet unsupportedSheet;
-                if (_unsupportedSheets.TryGetValue((Int32)(workbookView.ActiveTab.Value + 1), out unsupportedSheet))
+                if (UnsupportedSheets.TryGetValue((Int32)(workbookView.ActiveTab.Value + 1), out unsupportedSheet))
                     unsupportedSheet.IsActive = true;
                 else
-                    Worksheet((Int32)(workbookView.ActiveTab.Value + 1)).SetTabActive();
+                {
+                    Int32 sId = (Int32)(workbookView.ActiveTab.Value + 1);
+                    Worksheet(sId).SetTabActive();
+                    //- _unsupportedSheets.Keys.Where(n=>n <= sId ).Count()
+                }
             }
 
             LoadDefinedNames(workbook);
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Save.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Save.cs
index 9cbe188..08d6f97 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Save.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Save.cs
@@ -417,41 +417,26 @@
                                 select sheet;
 
             UInt32 firstSheetVisible = 0;
-            UInt32 activeTab = (from us in _unsupportedSheets where us.Value.IsActive select (UInt32)us.Key - 1).FirstOrDefault();
+            UInt32 activeTab = (from us in UnsupportedSheets where us.Value.IsActive select (UInt32)us.Key - 1).FirstOrDefault();
             Boolean foundVisible = false;
-            Int32 position = 0;
-            foreach (Sheet sheet in sheetElements)
+            //Int32 position = 0;
+            Int32 totalSheets = sheetElements.Count() + UnsupportedSheets.Count;
+            for (Int32 p = 1; p <= totalSheets; p++)
             {
-                position++;
-                if (_unsupportedSheets.ContainsKey(position))
+                if (!UnsupportedSheets.ContainsKey(p))
                 {
-                    Sheet unsupportedSheet =
-                        workbook.Sheets.Elements<Sheet>().Where(s => s.SheetId == _unsupportedSheets[position].SheetId).First();
-                    workbook.Sheets.RemoveChild(unsupportedSheet);
-                    workbook.Sheets.AppendChild(unsupportedSheet);
-                    _unsupportedSheets.Remove(position);
-                }
-                
-                    workbook.Sheets.RemoveChild(sheet);
-
+                    var sheet = sheetElements.ElementAt(p - UnsupportedSheets.Keys.Count(n => n <= p) - 1);
                     var xlSheet = Worksheet(sheet.Name);
                     if (xlSheet.Visibility != XLWorksheetVisibility.Visible)
                         sheet.State = xlSheet.Visibility.ToOpenXml();
 
-                    workbook.Sheets.AppendChild(sheet);
-
                     if (foundVisible) continue;
 
                     if (sheet.State == null || sheet.State == SheetStateValues.Visible)
                         foundVisible = true;
                     else
                         firstSheetVisible++;
-                
-            }
-            foreach (Sheet unsupportedSheet in _unsupportedSheets.Values.Select(us => workbook.Sheets.Elements<Sheet>().Where(s => s.SheetId == us.SheetId).First()))
-            {
-                workbook.Sheets.RemoveChild(unsupportedSheet);
-                workbook.Sheets.AppendChild(unsupportedSheet);
+                }
             }
 
             var workbookView = workbook.BookViews.Elements<WorkbookView>().FirstOrDefault();
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorksheet.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorksheet.cs
index 0a6017d..7dd52ed 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorksheet.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorksheet.cs
@@ -207,7 +207,7 @@
             get { return _position; }
             set
             {
-                if (value > Workbook.WorksheetsInternal.Count + 1)
+                if (value > Workbook.WorksheetsInternal.Count + Workbook.UnsupportedSheets.Count + 1)
                     throw new IndexOutOfRangeException("Index must be equal or less than the number of worksheets + 1.");
 
                 if (value < _position)