Display Settings- won,t save?
Maybe there are 2 problems:
1. You have recently installed a display card and you hadn't disabled your
old card, or onboard card. So they are crashed and only display in 640*480.
2. You have set your display in 32bit, try to use 16bit, it may be better.
Or, thirdly, you haven't pushed the "Apply" button.... (^^)