         setColumnCount(visibleColumns);  
         setIndexInView(firstColInView, lastColInView);
         layoutTarget.setContentSize(maxX, maxY);      	      
-        updateScrollRect(unscaledWidth, unscaledHeight);
     }
 
 

     *  @see lastIndexInView
     *  @see horizontalScrollPosition
     */
    override public function horizontalScrollPositionDelta(unit:uint):Number
    {
        var g:GroupBase = target;
        if (!g)

        var itemR:Rectangle = null;
        switch(unit)
        {
            case ScrollUnit.LEFT:
            case ScrollUnit.PAGE_LEFT:
                itemR = findLayoutItemBounds(g, firstIndexInView, -1, scrollR);
                break;

            case ScrollUnit.RIGHT:
            case ScrollUnit.PAGE_RIGHT:
                itemR = findLayoutItemBounds(g, lastIndexInView, +1, scrollR);
                break;

            default:
                return super.getHorizontalScrollPositionDelta(unit);
        }
        
        if (!itemR)
