I have been stuck using Catalyst 12.4 because any newer version of catalyst driver causes massive on screen glitches as soon as I start Windows. I have tried Catalyst v 12.6, 12.8 and the latest 12.10. Only 12.4 and earlier have worked okay for me.
What happens is as soon as I install the new catalyst driver then reboot, once windows has started, everything starts "glitching." Pieces of windows start moving and flickering all around my screens rapidly. Occassionally it will stop "glitching" momentarily, then start back up again.
The windows / programs I have open seem to influence the amount of flickering somewhat. For example a browser with a flash window seems to worsen the issue, but the issue is present even just having notepad or nothing open at all.
I was not able to take a screenshot using the print screen button (in fact, pressing the Prt Scr button momentarily stopped the visual glitching), but I made a .gif that pretty accurately shows the issue, other than that the flickering is actually a bit more random around the screen (this gif is only 3 frames):
I am running:
Win 7 x64
SAPPHIRE AMD Radeon HD 6870 1GB GDDR5 PCIE