diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/IXLCell.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/IXLCell.cs
index 1f2caba..e5d18c9 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/IXLCell.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/IXLCell.cs
@@ -127,12 +127,16 @@
         /// <value>The formula with A1 references.</value>
         String FormulaA1 { get; set; }
 
+        IXLCell SetFormulaA1(String formula);
+
         /// <summary>
         /// Gets or sets the cell's formula with R1C1 references.
         /// </summary>
         /// <value>The formula with R1C1 references.</value>
         String FormulaR1C1 { get; set; }
 
+        IXLCell SetFormulaR1C1(String formula);
+
         /// <summary>
         /// Returns this cell as an IXLRange.
         /// </summary>
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCell.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCell.cs
index 1cbc686..c52ace6 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCell.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCell.cs
@@ -1052,7 +1052,8 @@
 
         public Boolean IsMerged()
         {
-            return Worksheet.Internals.MergedRanges.Any(AsRange().Intersects);
+            using (var asRange = AsRange())
+                return Worksheet.Internals.MergedRanges.Any(asRange.Intersects);
         }
 
         public Boolean IsEmpty()
@@ -1231,7 +1232,10 @@
 
         private void ClearMerged()
         {
-            var mergeToDelete = Worksheet.Internals.MergedRanges.Where(merge => merge.Intersects(AsRange())).ToList();
+            List<IXLRange> mergeToDelete;
+            using (var asRange = AsRange())
+                mergeToDelete = Worksheet.Internals.MergedRanges.Where(merge => merge.Intersects(asRange)).ToList();
+
             mergeToDelete.ForEach(m => Worksheet.Internals.MergedRanges.Remove(m));
         }
 
@@ -2167,5 +2171,17 @@
         }
 
         #endregion
+
+        public IXLCell SetFormulaA1(String formula)
+        {
+            FormulaA1 = formula;
+            return this;
+        }
+
+        public IXLCell SetFormulaR1C1(String formula)
+        {
+            FormulaR1C1 = formula;
+            return this;
+        }
     }
 }
\ No newline at end of file
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCellsCollection.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCellsCollection.cs
index 35e4122..4ac6497 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCellsCollection.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCellsCollection.cs
@@ -198,6 +198,7 @@
         {
             int finalRow = rowEnd > MaxRowUsed ? MaxRowUsed : rowEnd;
             int finalColumn = columnEnd > MaxColumnUsed ? MaxColumnUsed : columnEnd;
+            
             for (int ro = finalRow; ro >= rowStart; ro--)
             {
                 for (int co = finalColumn; co >= columnStart; co--)
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Comments/XLComment.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Comments/XLComment.cs
index a644ad0..b93319f 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Comments/XLComment.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Comments/XLComment.cs
@@ -59,7 +59,19 @@
         public Int32 ExtentWidth { get; set; }
         public Int32 ShapeId { get; internal set; }
 
-        public Boolean Visible { get; set; }
+        private Boolean _visible;
+
+        public Boolean Visible
+        {
+            get
+            {
+                return _visible;
+            }
+            set
+            {
+                _visible = value;
+            }
+        }
 
         public IXLComment SetVisible()
         {
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook.cs
index cf57850..1c3e8aa 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook.cs
@@ -5,6 +5,7 @@
 namespace ClosedXML.Excel
 {
     using System.Linq;
+    using System.Data;
 
     public enum XLEventTracking { Enabled, Disabled }
     public enum XLCalculateMode
@@ -646,5 +647,23 @@
             Use1904DateSystem = value;
             return this;
         }
+
+        public IXLWorksheet AddWorksheet(String sheetName)
+        {
+            return Worksheets.Add(sheetName);
+        }
+
+        public IXLWorksheet AddWorksheet(String sheetName, Int32 position)
+        {
+            return Worksheets.Add(sheetName, position);
+        }
+        public IXLWorksheet AddWorksheet(DataTable dataTable)
+        {
+            return Worksheets.Add(dataTable);
+        }
+        public void AddWorksheet(DataSet dataSet)
+        {
+            Worksheets.Add(dataSet);
+        }
     }
 }
\ No newline at end of file
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Load.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Load.cs
index d2c89a4..ac7d02d 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Load.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Load.cs
@@ -352,7 +352,7 @@
             if (strokeWeight != null) drawing.Style.ColorsAndLines.LineWeight = Double.Parse(strokeWeight.Value.Substring(0, strokeWeight.Value.Length - 2), CultureInfo.InvariantCulture);
 
             var fillColor = shape.Attribute("fillcolor");
-            if (fillColor != null) drawing.Style.ColorsAndLines.FillColor = XLColor.FromHtml(fillColor.Value);
+            if (fillColor != null && !fillColor.Value.ToLower().Contains("infobackground")) drawing.Style.ColorsAndLines.FillColor = XLColor.FromHtml(fillColor.Value);
 
             var fill = shape.Elements().First(e => e.Name.LocalName == "fill");
             if (fill != null)
@@ -486,7 +486,7 @@
             LoadDrawingProtection<T>(drawing, clientData);
 
             var visible = clientData.Elements().FirstOrDefault(e => e.Name.LocalName == "Visible");
-            drawing.Visible = !(visible != null && visible.Value.ToLower() == "false");
+            drawing.Visible = visible != null && visible.Value.ToLower().StartsWith("t");
 
             LoadDrawingHAlignment<T>(drawing, clientData);
             LoadDrawingVAlignment<T>(drawing, clientData);