I have a nVidia 7500 LE (Crap, i know. Upgrading soon) and after switching back from my TV to my monitor, it will go all bright and stuff, the only way to sort it out is rebooting.
I have the Latest drivers from nVidia, it happened with the older ones too.
I know its not the monitor, as i have dual monitors and switched the plugs around.
Here is a picture..
Any ideas on how to stop this, or fix without reboot?