         
         const columnLeft:Number = grid.getCellX(0, columnIndex);
         const columnRight:Number = columnLeft + grid.getColumnWidth(columnIndex);
-        const smw:Number = columnHeaderGroup.separatorMouseWidth;
+        const smw:Number = columnHeaderGroup.getStyle("separatorAffordance");
         
         if (!isFirstColumn && (x > (columnLeft - smw)) && (x < (columnLeft + smw)))
             return grid.getPreviousVisibleColumnIndex(columnIndex);

    
    //---------------------------------------------------------------
    //
    //  Internal methods
    //
    //---------------------------------------------------------------    
    

        const visibleColumnIndices:Vector.<int> = grid.getVisibleColumnIndices();
        const oldRenderers:Dictionary = new Dictionary();

        const overlayGroup:Group = this.overlayGroup;
        const columnSeparatorFactory:IFactory = columnHeaderGroup.columnSeparator;
        var renderer:IGridItemRenderer;
        var column:GridColumn;
