I'm having an odd error on 12.10. I can't change my display resolution to anything but the laptop's native (1440x900) resolution. I noticed this a couple weeks ago when I tried to attach to a projector, but it's annoying for games too. In nvidia-settings, there are no other resolutions listed, whereas before, I could select 1280x800, 1024x768, etc.
The card is a GeForce 8600M GT, and I upgraded to the 310 experimental drivers to try to solve this, but no joy.