TitleWindow with TextInput throws exception on close using mobile skins

reproduce:
1. create a mobile flex project and run on mobile device
2. create TitleWindow with TextInput child
3. open popup using PopUpManager
4. try to close the popup using close button
5. see the exception

Main Thread (Suspended: TypeError: Error #1034: Type Coercion failed: cannot convert mx.events::CloseEvent@6a1699d1 to spark.events.PopUpEvent.)
flash.events::EventDispatcher/dispatchEventFunction [no source]
flash.events::EventDispatcher/dispatchEvent [no source]
mx.core::UIComponent/dispatchEvent
spark.components::TitleWindow/closeButton_clickHandler

reason:
my best guess is it is somehow mobile skin related

possible fix:
extend TitleWindow and do
override protected function closeButton_clickHandler(event:MouseEvent):void
{
dispatchEvent(new PopUpEvent(PopUpEvent.CLOSE));
}