Brightness problem when playing games

I've been having this weird graphics problem with all 3 of my past gfx cards (all happens to be ATI). Can't remember the oldest one now, last one was a 9800 pro and now a X850XT.

Problem is that whenever I play games like warcraft 3 for example, it changes my gamma and brightness back to default. Not a problem until I go off to play CS and my colour is changed to the default colours. I exit the game and dispite the settings in the colours (both desktop and fullscreen 3D) are at my own settings the colours are at default. I click apply again and it's back to normal, until I start CS again that is to see the colours back to default. Sometimes it'd go back to my settings after a few tries, sometimes I have to reboot to get it back to normal.

Any idea how to fix this annoying problem?