I have the same problem with either IE8 or FF...
embedding youtube videos doesn't seem to work. It just displays a blank white space. But yet I've seen other posters embed them just fine, and I've not had a problem doing so myself untill just recently.
Either the method for embedding has changed, thus I'm doing it wrong, or the embed function ain't workin' right. I've noticed other members seeming to have the same problem.
Just figured I'd throw this out there in case there is a bug or somethin'.