Datagrid won't highlight

Ver开发者_运维问答y bizarre issue here: For whatever reason, my datagrid will not highlight items as I roll my mouse over them. Instead, the highlight bar just remains static on the last entry in the datagrid. I know I can still select items as I have written methods that respond to the selection. Anyone have any ideas? Here is the datagrid:

<mx:DataGrid x="323" y="245" width="286" dataProvider="{allBanks}"  
            id="bank" rowCount="4" >
    <mx:columns>
        <mx:DataGridColumn dataField="bank" headerText="Bank Name"/>
    </mx:columns>
</mx:DataGrid>

I guess the problem is in uid attributes of data items of your data provider. If uids are the same (maybe as a result of cloning of some other logic) DataGrid, which relies on unique uid, can't determine the exact item to highlight.