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

                caretColumnIndex =  _columns.length - 1;
            dispatchCaretChangeEvent();
            caretChanged = false;
        }            
    }
    
    /**

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