I'm having a problem here with my G4 Sawtooth on OSX 10.2.4- first time since installing OSX. When I choose "Shut Down" under the Apple Menu, it starts the process, the little circle stops early and then the computer restarts itself. Could anyone help here? How can I shut it down, and what might the problem be? It's never done this before, and all I've done is allow the computer to stay on overnight, which I do on occasion.