nVidia provides a driver package for for the nForce2 on Linux
here. Depending on your distro, there might not be an RPM for it so scroll down to the bottom of the list, grab (and read) the README, and pick one of the source packages. I have been running Linux on an A7N8X for around a year now with no problems, though I don't use the nVidia drivers. I used them when I first installed, but they didn't work very well then. There is support for the nForce2's hardware in the kernel, but that would likely require a kernel recompile.
The drivers have passed the stable 1.0 version now and should be fine so give them a try.
There is a post
here with detailed instructions on using 'imwheel' to enable the side buttons on a mouse. I have heard of many people getting this to work successfully, I just never bothered personally
As far as the error message, we'll have to know what it is before we can help.
Good luck!