screen brightness resetting itself

[skolnick]

Hi!

My issue is like this: I have a laptop (dell vostro 1400, NVidia 8400M video card) running Fedora 12 up to date. My desktop is KDE 4. I usually run the laptop connected to the power outlet, so my power profile is set to "performance". This power profile sets the screen brightness to the maximum. However, when I'm in the dark, I want to lower the screen brightness. The shortcut keys work, and the screen brightness is lowered. However, for some reason, after about 30 seconds it resets itself to the highest brightness setting. No matter how I set the brightness, it will always reset itself. Any ideas what can i do to correct this?

Thanks!