Which card exactly?
Is your driver up to date?
I would have recommended 12.2.
What version of the display driver did you have before?
Did you reboot after the install (the installer doesn't encourage you to do so, but it's a good idea)?
What OS version are you using? I don't have a quick idea about the GPU (other than avoiding 12.4 for ATI), but it looks like you might be using the 32-bit Ps application (based on the available RAM).