         
         // Only invalidate if we're clipping and scrollR extends outside validBounds
         
-        // FIXME: the hover indicator may need to be updated if the grid
-        // underneath the pointer scrolls.
-        
         const scrollR:Rectangle = grid.scrollRect;
         if (scrollR && !visibleItemRenderersBounds.containsRect(scrollR))
             grid.invalidateDisplayList();

        
        const scrollX:Number = horizontalScrollPosition;
        const scrollY:Number = verticalScrollPosition;
        
		updateGridDimensions(scrollX, scrollY, unscaledWidth, unscaledHeight);


    {
        const r:Rectangle = visibleItemRenderersBounds;
        const width:Number = 1;  // TBD: should be max(1, rowGap)
        const height:Number = Math.max(r.height, visibleGridBounds.height); 
        const bounds:Rectangle = gridDimensions.getColumnBounds(columnIndex);
        if (!bounds)
            return;
