I installed Internet Explore 9RC, Windows 7 SP1 and updates KB2482017 and 2475792

and now I cannot watch videos in Youtube. The sound starts but the screen turns green and Youtube stops responding to the point that it needs to be stopped with the task manager. I have tried everthing, went back to IE8, downloaded newest video
driver, uninstalled, went back to IE9, unisntalled Flash, etc. This is Crazy! This happens with Firefox, Chrome, and Safari.
I'm using Windows 7 professional 64-bit on an intel quad core 8200, 4GB RAM, Asus motherboard P5KPL-CM and Radeon 4550 video card. Your help will be appreciated