     
     private var _itemRenderer:IFactory = null;
     
+    private var itemRendererChanged:Boolean = false;
+    
     /**
      *  The item renderer that's used for columns that do not specify one.
      * 

        
        _itemRenderer = value;
        
        invalidateSize();
        invalidateDisplayList();
        gridLayout.clearVirtualLayoutCache();
        if (gridLayout.gridDimensions)
            gridLayout.gridDimensions.clearTypicalCellWidthsAndHeights();
        
        dispatchChangeEvent("itemRendererChanged");
    }    

        {
            if (rowHeightChanged)
                gridDimensions.defaultRowHeight = _rowHeight;
            gridDimensions.variableRowHeight = variableRowHeight;
            
            if ((!variableRowHeight && rowHeightChanged) || variableRowHeightChanged)
            {
