I recently picked up a top of the line, high-res 1.67GHz PowerBook G4 & overall have been absolutely chuffed with it. However this morning when I went to turn it on & began to use my USB mouse - only to find it wouldn't work. So logically thinking - I tested the built in trackpad & found that worked brilliantly. I then went in to System Profiler & checked to see if the mouse was actually recognised by OS X & sure enough it was. The mouse's optical laser blinks on then off every second or so - almost as if it's not receiving power from the hub correctly. I reset the PRAM & PMU to no avail. Any ideas? PS. The same issues persists regardless of the USB device, be it a flash drive, keyboard, phone etc. All don't work.