Gamma resets to bright (1.0?) instantly

[helopticor]

I'm running Penumbra Overture (from the Humble Bundle) on Windows 7 64-bit with an NVIDIA GeForce 310M card.

As far as I can tell, everything works fine except the gamma setting. When I change the gamma (up OR down) the screen usually flashes to what I assume is the correct brightness for a half second (sometimes it doesn't even do this), and then appears to revert to the same level (presumably 1.0). The fact that the gamma number can go below or above 1.0 doesn't seem to affect the permanent brightness.

This makes the game way too bright even when my laptop screen brightness is as low as it goes.

I searched the technical support threads and the only similar thing I could find seems to be this one, and I'd like to play on easy if possible.

Does anyone have any suggestions?

P.S. I had been using Steam to run it, but I get the same problem even when I run it directly, so it's not the Steam overlay or anything.

Edit: I figured it out. The moral of the story is don't have a program that controls the screen brightness running in the background. Sorry for the spam; feel free to close this thread.