Video not displaying (black box over player) or cannot seek/scrub (weird or no scroll

[Howell]

If you are experiencing:
1) A black, white, or colored box (with or without a line through it) over the video player
2) A wonky looking (or no) scroll bar
3) Your video stops playing when you try and change your resolution

...you've come to the right place. Our engineers are aware of this issue and are working hard with Adobe to try and work it out as soon as possible. Please use the following workarounds in the meantime:

http://www.google.com/support/forum/p/youtube/thread?hl=en&tid=782d433caef8ec2b&start=240


I also saw problems with Hulu video not appearing in full screen.