In an AdvancedDataGrid using an MXAdvancedDataGridItemRenderer, mouseover was not being passed on to the AdvancedDataGrid.
After days of struggle, I wanted to share this:
In your data setter, assign super.data with the new value for mouse events to be bubbled (?!)
Example (doesn't work)
override public function set data( value:Object):void {
var latency:Number = value[ ( this.listData as DataGridListData).dataField] as Number;
// Do cool stuff
Example (works)
override public function set data( value:Object):void {
var latency:Number = value[ ( this.listData as DataGridListData).dataField] as Number;
super.data = value;
// Do cool stuff
The example above works. Hope it can save you the time it took me to figure out.