display settings revert after restart?

For some reason my display settings change from what I set them to to default settings (680), which are way too large. I click on properties and set like I want them, but just as soon as I turn the computer back on they have changed back to 680 x 60 mhz rather than the 720 x 75 mhz. Any ideas? Thanks!

If you are OCed drop it back to stock and see if it still does it.

Did not make a difference. I backed off to stock and still no success. I need to mention that my oc has been perfect for six months. Temps cool, psu looking strong, system scores are nice and tight. I'm wondering if an optimizing program could be responsible. I have tried a few, but can't tell which one may have caused this problem. I have since deleted all and problem still exists. Do you think a registry value could have been changed and that is my problem? No matter how many times I change from 640 x 480 and 60 mhz back to 1024 x 768 and 75 mhz, as soon as I turn off my mach. and restart, it resets back to 640 x 480 and 60 mhz.

anyone?