focus does not move correctly when there are multiple non-modal popup windows

focus does not move correctly when there are multiple non-modal popup windows.
The main application flex_popupwindowssample calls a modal window FlexTestPopUpChild1, which in turn calls a non modal window FlexTestPopUpChild2.
The FlexTestPopUpChild1 contains an option to launch multiple instances of FlexTestPopUpChild2 window.
If there are multiple instances of FlexTestPopUpChild2 open , then if we click tab button on a instance of FlexTestPopUpChild2 other than the latest one, then the focus shifts back to the latest instance of FlexTestPopUpChild2 rather than selected instance of FlexTestPopUpChild2 .