After my G4 Mdd 1 gig dual is on for a few hours, it reboots itself no matter what I am doing. I could be at a web page or listing to music or watching a video. Once it reboots itself like that it will do it again within 15 minutes or so. When it does stay on for a few hours I will check disc permissions and it will find at least 20 that need repair. It repairs them and everything is fine till it starts rebooting again. Then I come up with bad disc permissions again. How can they be bad every few days? I was thinking ram. Could someone point me in the right direction. I am running Leopard 10.5.8. This is my first experience with a Mac and so far it has not been a happy one. p.s. This is happening on more than one hard drive.