I have formatted the pc and installed the lastest drivers for my sapphire radeon hd 7990. It doesn't freeze always, and it doesnt freeze in youtube, but it does in xhamster (hehe). When it freezes the screen goes grey with blue lines.
Thanks in advance!
More aboutfreezes playing flash player videos
You may try turning off Hardware Acceleration in Flash content. For this, right-click on a flash video and uncheck use hardware acceleration.