Jason,
Are you sure it is the same issue?
I was reading the thread you are referring to where there was tearing in the browser but not in XBMC when playing Youtube videos. My issue is the video just struggles to play in in the browser, becomes out of sync, and the frame rate generally suffers. I'll try to play the video without going fullscreen when I get home and I'll also check the CPU usage levels.
How do these types of issues usually get resolved, by you sending these problems to the drivers "people"?
Thanks a lot for the support,
David