FP freezes in Internet Explorer in wmode = 'window' and looses ExternalInterface callbacks

Hello!

Our app is added using SWFobject in FaceBook, when trying to make payment in FaceBook its api sets visibility='hidden' to flash container. At this time Scout shows that FP19.0.0.266 freezes and frames stop (enter frame and timers do not trigger). After closing payment screen visibility is set back to 'visible', enterfame and timers start to "respond" but ExternalInterface callbacks disappear. In other browsers (tested in Chrome and Firefox) FP19.0.0.266 doesn't freeze and all events and timers work correct.

How can we make FP work correct during visibility set to 'hidden' for its container/wrapper?