I've used many different drivers 12.8, 12.10, 12.11 beta w/CAP2
I'm on my 2nd 7970 as the first was RMA'd due to the same problems and also having artifacting in assassins creed 3, this one does not have it in assassins creed 3 but i get the same problem http://postimage.org/image/phrju2gw3/ http://postimage.org/image/lver3g93h/ http://postimage.org/image/3ya26debn/
those happen, this is my second card it happens in youtube videos/flash player
also it doesnt happen when i turn on hardware acceleration. But hardware acceleration uses the card for rendering videos? So i think its the card, i mean i don't feel right returning a second dud card? from XFX R7970 Black Edition OC
Sigh.. another XFX card issue. XFX must have huge QC issues.
Anyways, if you've tried multiple drivers, it might be the card. I'm not sure I understood correctly, is this your second 7970 after RMAing or your second 7970 in crossfire? Like do you have one or two.