I'm using Windows Vista and Chrome.
When I use the YouTube module, I get lots of weirdness. Let me see if I can explain it. The YouTube vids remain on top of whatever module I'm trying to edit. So when I go to edit a text module, I can't see the module well because of the videos in the way. Sometimes I can drag the module out of the way enough to make do, but it's a real pain and sometimes I've had to absolutely close the entire tab when I was trapped and couldn't get out.
I hope this screenshot helps you see the issue. See how the article module is trapped behind the YouTube modules?