well you know when something happens outside of cod and you have to take care of it, you have to minimise cod, well when you come back, the screen is sometimes darker and unplayable, so you have to restart the game, which takes time. there was a file that was supposed to fix this, does anyone possibly know where it is?....
i had the same problem, all you do is go into your settings and turn the brightness up.
If you have an ATi video card, when ingame, drop down console and type:
Press Enter, and next time you play, no more darker screen.