Gamma won't reset.

[Shrimp]

I installed a Samsung 226bw today, but I'm having trouble with the gamma. I went into MagicTune and did the color calibration which seemed to get it all set up right, but when I exit a full screen game, it won't go back to the default settings. Some games I can enter and exit and it'll fix the gamma, but sometimes it won't.

I'm on an ATI card if that helps.

Any help?