Hey, I am running a 15" 1.25GHz PowerBook G4 with Mac OS 10.2.7 installed. Every time that I try and boot up, the computer goes the entire way, and then....frozen! (the trackpad that is).....i tried to plug in a usb pro mouse...doesnt work. EVERYTHING else in the system works except for the mouse. i can browse through applications and files using the keyboard, no problems launching anything. So strange. Everything was working fine before i tried to upgrade to panther 10.3......HELP!