Still having this issue and have been unable to resolve it. Would love any help.
I had a similar problem. I fixed by restarting photoshop and then changing my foreground color to white and my background to pale yellow. Before that they had been white and black and I reversed them a couple of times trying to fix it.
Same issue here. Very frustrating. Is there a fix to this? I'm using a Radeon 7000 series card, Windows 7 Ultimate, a tons of memory- - this is a first.
Check to see if there are any updated drivers for your card. http://support.amd.com/en-us/download
The standard advice is to get the latest driver from the Graphics card maker rather than Microsoft or your PC maker.