Laptop monitor power

I installed SuSE 9.0 on my Compaq Presario 2800T. I also installed and use Ximian Desktop 2 for my primary desktop. When I initially installed SuSE, the button that would shut off the monitor when the laptop was closed up worked, but now it doesn't. In fact, neither that nor my track pad work anymore. I don't care so much about the track pad, but does anyone know how I can re-enable the monitor power button so that the monitor will shut off when I close the laptop (with the computer still on)?