Last week we lost power and for some reason my Dual 450 started up on it's own (it's on a UPS). Ever since then I haven't been able to shut it down. Whenever I choose "Shut Down" from the Apple menu I get the "Cancel/Shutdown" prompt, click "Shut Down" and it goes through the regular shut down cycle. Then, as soon as the light in the power button goes off, it automatically starts back up. I've zapped the PRAM and checked the system pref to make sure the box for auto restart at power failure is off (it always has been, by the way). Can't figure this out. Running OS 10.2.5. Any suggestions?