I think you should have a look at this thread. I suspect Fedora has simply misconstrued the refresh rates. Sorry, I didn't feel like typing it all up once again.
Edit: I see you use Nvidia 8800; you should bear in mind that this card was poorly (if at all) supported under Linux until recently. Maybe this issue has been resolved by now, don't know. Even so, you've installed a distribution that is older than you hardware: surely you can't expect it to recognize a card that didn't exist at the time? Follow the steps described in the thread above and also look for the "device section" in xorg.conf; you should make driver "vesa". If it works, you'll still have to go to Nvidia and download the Linux driver for your type of card.