DataGrid Sort Anomoly

[Jack Ring]

Is there any reason that a Spark Datagrid will NOT SORT if you use...

   <s:DataGrid id="exDg" sortableColumns="true" >
   <s:AsyncListView list="{exampleAc}" />
</s:DataGrid>

But it WILL SORT if you use...

<s:DataGrid id="exDg" dataProvider="{exampleAc}" sortableColumns="true"
></s:DataGrid>

Thanks,

Jack Ring