I've just received the Sapphire Radeon 6870, installed the latest driver (11.10) and I'm having an odd graphical problem with Photoshop and other software. In fact, the website title text on my Firefox windows is 'fractured' too.
The problem is difficult to describe, please see the image.
You ever get this fixed? Are you overclocking? Could be a overheating issue. I recently overclocked my 6870 and I noticed those squares myself appear in Crysis when I took it too far. Might want to go into Catalyst Control Center or download TRiXX and manually crank down the speed of your memory clock. Little squares disappeared after that for me. Just for reference, here's some info I got from some other site via Google: