I have a G4 powerbook Titanium 1GHZ and when i choose the shutdown option, it continually just reboots and is driving me crazy!! I just ordered a brand new battery because the battery in it won't hold a charge....seems to be common..... but i was wondering if anyone has any feedback to help....i already tried to have it hooked up without the battery in it and only the battery chord but it still won't shut down....i've been told the logic board could be bad.....but would love to hear others experience...thanks!