You need to go to this site:
Platform/nForce Drivers (in the first box)
Unified driver package (in the second box)
Linux (in the third box)
Press the "Go!" button.
Follow the instructions on this page.
You will also need to alter a few other things to get the module to load properly. See the other forums on how to accomplish this. If you are still having problems post back here.
I am running this now, but I've noticed that things are less than stable... good luck