Full Screen problems

I've recently been having problems playing games fullscreen.  Whenever I play a fullscreen game, the monitor acts as if it's not getting a signal for a second (which I assume is normal) then proceeds to change resolution and go to full-screen mode.  Once it starts up, though, it sometimes shows the background in the new resolution, but just that part that fits in that resolution, meaning to task-bar and missing icons, and I end up having to alt-tab into the program that is fullscreen.  After that everything works like normal until I want to quit, at which point the monitor acts like its not getting a signal for a second then changes back resolution, only there's nothing on the screen except my mouse and a black background.  I can't see or do anything except move my mouse around the screen.  Ctrl-Alt-Del doesn't even do anything, even if I press and hold it twice, which should reboot.  Alt-tab does nothing, right click does nothing, absolutely nothing happens.  I end up having to manually reboot the machine every time I play a fullscreen game!  This didn't use to happen and I don't remember changing anything since.  This even happens when I play fullscreen games at a resolution that is the same as my desktop resolution.  What is going on?

Do you happen to use any custom shells, transparent window tools etc.?

I'm not CURRENTLY running litestep, but I do have that.  I'm not running any transparant window tools, but I do have a program that makes my desktop icons' text backgrounds' transparant (I'm running 2K), but this isn't anything new.  Also, I know it's not the same thing.

If it helps I'm running on an LCD screen via DVI connected to an AGP GeForce 6800 OC.

I reinstalled the driver and now the problem doesn't happen with at least one game that it happened in before, but it still happens in at least one other game.