Ok I've got a Mirrored Drive Door Dual 1GHz PowerMac G4. Just recently it started acting up. When I power on it goes through its regular start up and then the screen fades dark and says I need to restart the computer. So I do and it just keeps doing it. I reset the PRAM and was able to boot up and it started fine. Then the next day it started acting up all over again. Anybody got any ideas as to whats going on and how I can remedy this. Thanks.