Brightness issues in Thief 3

[Malygris]

Playing Thief 3, and I alt-tab a lot. I know it's not supported, but I do it, and it's not going to stop. I also know other people in the same situation who do the same thing and have no problem.

My problem is, everytime I alt-tab back into the game, the darkness drops all the way down, so it's very difficult to see. I'm playing with the darkness set to 10, and when I go back into the game, I have to go to the video settings area and re-adjust the brightness. Thing is, the brightness is still set to 10, but I have to slide it up (or down) one notch and then back to 10, and suddenly it gets much brighter, and away I go.

I'm running Windows XP with a Radeon 9500 Pro, latest Catalysts installed. (Put them in last night.) It's really annoying. Does anyone know how to make this stop?

Thanks.