It was changed around 4.10 [1] . The change to public enabled a common method between the listbase components and the grid/datagrid components. This change supported a new interface that implements a simple navigation that can be commonly used between those components [2].
No mx_internal is required for that method now to override it. It should work like this now... override public function setSelectedIndex(rowIndex:int, dispatchChangeEvent:Boolean = false, changeCaret:Boolean = true):void { super. setSelectedIndex (rowIndex, dispatchChangeEvent, changeCaret); } [1] http://flex.apache.org/asdoc/spark/components/supportClasses/ListBase.html#setSelectedIndex() [2] http://flex.apache.org/asdoc/spark/components/supportClasses/IDataProviderEnhance.html -Mark