diff --git a/layout/html/table/src/nsCellMap.cpp b/layout/html/table/src/nsCellMap.cpp
index 5645d8b89fab..4c84f1208899 100644
--- a/layout/html/table/src/nsCellMap.cpp
+++ b/layout/html/table/src/nsCellMap.cpp
@@ -311,10 +311,16 @@ nsTableCellMap::AppendCell(nsTableCellFrame& aCellFrame,
                            PRBool            aRebuildIfNecessary)
 {
   NS_ASSERTION(&aCellFrame == aCellFrame.GetFirstInFlow(), "invalid call on continuing frame");
+  nsIFrame* rgFrame = nsnull;
+  aCellFrame.GetParent(&rgFrame); // get the row
+  if (!rgFrame) return 0;
+  rgFrame->GetParent(&rgFrame);   // get the row group
+  if (!rgFrame) return 0;
+
   PRInt32 rowIndex = aRowIndex;
   nsCellMap* cellMap = mFirstMap;
   while (cellMap) {
-    if (cellMap->GetRowCount() > rowIndex) {
+    if (cellMap->GetRowGroup() == rgFrame) {
       return cellMap->AppendCell(*this, aCellFrame, rowIndex, aRebuildIfNecessary);
     }
     rowIndex -= cellMap->GetRowCount();
diff --git a/layout/html/table/src/nsCellMap.h b/layout/html/table/src/nsCellMap.h
index c24cf0cf98b3..02612ba14eec 100644
--- a/layout/html/table/src/nsCellMap.h
+++ b/layout/html/table/src/nsCellMap.h
@@ -211,8 +211,8 @@ public:
   PRInt32 GetNumCellsOriginatingInRow(PRInt32 aRowIndex) const;
   PRInt32 GetNumCellsOriginatingInCol(PRInt32 aColIndex) const;
 
-  /** return the actual number of rows in the table represented by this CellMap */
-  PRInt32 GetRowCount() const;
+  /** return the number of rows in the table represented by this CellMap */
+  PRInt32 GetRowCount(PRBool aConsiderDeadRowSpanRows = PR_FALSE) const;
 
   nsTableCellFrame* GetCellInfoAt(nsTableCellMap& aMap,
                                   PRInt32         aRowX, 
@@ -374,9 +374,10 @@ inline nsTableRowGroupFrame* nsCellMap::GetRowGroup() const
   return mRowGroupFrame;
 }
 
-inline PRInt32 nsCellMap::GetRowCount() const
+inline PRInt32 nsCellMap::GetRowCount(PRBool aConsiderDeadRowSpanRows) const
 { 
-  return mRowCount; 
+  PRInt32 rowCount = (aConsiderDeadRowSpanRows) ? mRows.Count() : mRowCount;
+  return rowCount; 
 }
 
 // nsColInfo
diff --git a/layout/tables/nsCellMap.cpp b/layout/tables/nsCellMap.cpp
index 5645d8b89fab..4c84f1208899 100644
--- a/layout/tables/nsCellMap.cpp
+++ b/layout/tables/nsCellMap.cpp
@@ -311,10 +311,16 @@ nsTableCellMap::AppendCell(nsTableCellFrame& aCellFrame,
                            PRBool            aRebuildIfNecessary)
 {
   NS_ASSERTION(&aCellFrame == aCellFrame.GetFirstInFlow(), "invalid call on continuing frame");
+  nsIFrame* rgFrame = nsnull;
+  aCellFrame.GetParent(&rgFrame); // get the row
+  if (!rgFrame) return 0;
+  rgFrame->GetParent(&rgFrame);   // get the row group
+  if (!rgFrame) return 0;
+
   PRInt32 rowIndex = aRowIndex;
   nsCellMap* cellMap = mFirstMap;
   while (cellMap) {
-    if (cellMap->GetRowCount() > rowIndex) {
+    if (cellMap->GetRowGroup() == rgFrame) {
       return cellMap->AppendCell(*this, aCellFrame, rowIndex, aRebuildIfNecessary);
     }
     rowIndex -= cellMap->GetRowCount();
diff --git a/layout/tables/nsCellMap.h b/layout/tables/nsCellMap.h
index c24cf0cf98b3..02612ba14eec 100644
--- a/layout/tables/nsCellMap.h
+++ b/layout/tables/nsCellMap.h
@@ -211,8 +211,8 @@ public:
   PRInt32 GetNumCellsOriginatingInRow(PRInt32 aRowIndex) const;
   PRInt32 GetNumCellsOriginatingInCol(PRInt32 aColIndex) const;
 
-  /** return the actual number of rows in the table represented by this CellMap */
-  PRInt32 GetRowCount() const;
+  /** return the number of rows in the table represented by this CellMap */
+  PRInt32 GetRowCount(PRBool aConsiderDeadRowSpanRows = PR_FALSE) const;
 
   nsTableCellFrame* GetCellInfoAt(nsTableCellMap& aMap,
                                   PRInt32         aRowX, 
@@ -374,9 +374,10 @@ inline nsTableRowGroupFrame* nsCellMap::GetRowGroup() const
   return mRowGroupFrame;
 }
 
-inline PRInt32 nsCellMap::GetRowCount() const
+inline PRInt32 nsCellMap::GetRowCount(PRBool aConsiderDeadRowSpanRows) const
 { 
-  return mRowCount; 
+  PRInt32 rowCount = (aConsiderDeadRowSpanRows) ? mRows.Count() : mRowCount;
+  return rowCount; 
 }
 
 // nsColInfo