Is it X that you are having problems? RedHat, Mandrake etc...Set things up so that you don't have to, but depending on your mouse, Slack needs some configuration, manually that is. No fancy pants gui's. So the question is, is it USB or is it really PS/2? If it's USB you may want to load the appropriate modules from /etc/rc.d/rc.modules by uncommenting the line. Better yet, you may want to recompile the kernel only with the options you want. It'll speed things up and is a good idear anyhow. There is a file here: /usr/src/linux-2.4.5/Documentation/usb/input/input.txt
that will give you ideas of what you may want your rc.gpm and XF86Config to be...