Error making chart components selectable in Flex

[derm116]

Hi all,

I'm getting the following error when I make a bubblechart selectable

TypeError: Error #1034: Type Coercion failed: cannot convert mx.charts.events::ChartItemEvent@41747c1 to mx.events.IndexChangedEvent.
at flash.events::EventDispatcher/dispatchEventFunction()
at flash.events::EventDispatcher/dispatchEvent()
at mx.core::UIComponent/dispatchEvent()[E:\dev\3.0.x\frameworks\projects\framework\src\mx\ core\UIComponent.as:9051]
at mx.charts.chartClasses::ChartBase/http://www.adobe.com/2006/flex/mx/internal::selectItem()[C:\Work\flex\dmv_automation\projects\datavisualisa tion\src\mx\charts\chartClasses\ChartBase.as:2503]
at mx.charts.chartClasses::ChartBase/processRollEvents()[C:\Work\flex\dmv_automation\projects\datavisualisa tion\src\mx\charts\chartClasses\ChartBase.as:2277]
at mx.charts.chartClasses::ChartBase/mouseDownHandler()[C:\Work\flex\dmv_automation\projects\datavisualisa tion\src\mx\charts\chartClasses\ChartBase.as:4248]

The only code I changed was

adding in the following to the <mx:bubbleChart tag
selectionMode="multiple"

and making by bubbleseries selectable
bs.selectable=true;

Anyone have any idea why I'm getting this error!?

Thanks,
Derm