Are you using the new flash player 10? I've seen some display bugs while using this new version of flash player.
(The white overlay seems to be caused by the flash content (the blip-tv player) ).
I've turned off a lot of the CSS (using FireBug in FF) to try to see if there would be any of it that would cause some problem, but no luck there.
Give us some more feedback on your tests.
*EDIT
Forget about my first intuition... The probem seems to be caused by the use of the z-index property in one of your "footer" sections... z-index is a strange beast and should be used with care... maybe setting a z-index to your blip.tv container might solve the issue, maybe it won't. Make sure to make it play nice with IE7 at least, even if it's annoying to figure out the best combination to satisfy this beast. (IE implementation of the z-index property is sub-par at best...)
Hope this helps!