YouTube Problem

From today, for some reason i cant watch videos on youtube..
The site works but the video screen is totally black and nothing happens. I have checked the JavaScript and also i re-installed Adobe Flash Player but still nothing..I am using Firefox-Windows 7.
The problem is only on youtube, anywhere else i can watch videos. I also tryed using youtube on IE but nothing changes..

I found a topic with some other users having the same problem http://www.google.com/support/forum/p/youtube/thread?tid=526ffe8ce06f841f&hl=en&fid=526ffe8ce06f841f00049cf1e4227c8f

I've got the same problem (see my thread a few threads below this one), it's really annoying. I'm using Firefox and Windows Vista.

Mine today was just fine..i dont get why this happened anyway...