mouse, works on install but not after reboot

well, my set-up went fine - the mouse functioned normally, however, when i rebooted it went off and scanned for hardware and could not find my mouse. It asked for me to enter the mouse and i choose the same one the installation program used (tabbed to accept and continued). the kdm screen came up with the X for the mouse but no action from the mouse. it is driving me nuts. Dana VanEyck, B.Sc.