Hi, I had this problem before and it was only a nuisance, now it's a real problem. I cannot set my display higher than 1024x768, although before I replaced the motherboard/reformated, I was able to. I just installed Need for Speed Underground 2, and I can't put it higher than 800x600, and setting the detail past the third notch crashes my system. I've only tried to play the game once, and it froze up during the first cut scene, and every time it switches screens, my moniter settings go all crazy. I have the latest drivers.

bumpity bump

Does your monitor have controls right on the frame of the monitor itself.I have seen these overide (limit)the control in the GUI.

Yea, it does... but I have had my display settings up high before with no trouble. Also, I've tried the game several times now, and it freezes at random during play, sometimes in the opening menu, other times I can get halfway through a race before it freezes... Beginning to think that that's not a video card problem.

Well sound like standard troubleshooting.
Uninstall the card(drivers) and revert to standard vga drivers,test settings on the monitor.(you should confirm minimum requirements for that game).
You may have to test that monitor and/or card in another machine if you can.
Also shutoff every possible running service you can and test the game.
Let us know what you have done and how it's going.