             const lastColumnIndex:int = gridDimensions.columnCount - 1;
             
             visibleHeaderSeparators =  layoutLinearElements(factory,
-                columnHeaderBar.overlayGroup, visibleHeaderSeparators,
+                columnHeaderBar.overlayLayer, visibleHeaderSeparators,
                 oldVisibleColumnIndices, visibleColumnIndices, 
                 layoutHeaderSeparator, lastColumnIndex);
         }

    
    private function layoutCellElements (
        factory:IFactory,
        container:IVisualElementContainer,
        oldVisibleElements:Vector.<IVisualElement>,
        oldVisibleRowIndices:Vector.<int>, oldVisibleColumnIndices:Vector.<int>,
        newVisibleRowIndices:Vector.<int>, newVisibleColumnIndices:Vector.<int>,

            freeGridElement(elt);
        elements.length = 0;
    }      
    
    /**
     *  @private
