Changed aspect ratio... now games crash

I have an HP NC8430 with a Mobility X1600. I tried changing the settings in the ATI Control Panel to “centered” so that it wouldn't stretch an image displayed at non native resolutions. In this case the game is HL2: Episode One. However I decided that I would rather have the image stretch rather than have the black segments, and changed it back to the original “Full Panel Size” setting. But now, after playing the game for a little while, I’ll get sent back to the windows desktop and a black window will jump from the resolution I have set in the game (1280X768) and a complete black screen. It seems like the display keeps flipping between and 1280X768 and 1680X1050 resolutions. I just tried upgrading to the latest mobility catalysts and the same thing happens.

Also, when I wake my laptop from standby, I find that often it starts up at some insanely low resolution like 600X800 i'm not sure what the setting actually is because the laptop thinks its still running at 1680X1050. When I log into my desktop the desktop scrolls, like the map in a strategy game or something. If i put it in standby and rewake it up, everything is fine.

no one?