My dads Intel Mac Mini has been working great. About two weeks ago I installed 2 gigs of Crucial RAM and it's was working even better. Today he told me all he had was the rainbow pinwheel spinning, so I looked at it. Mail and Safari were both not responding and they wouldn't force quit. I tried restarting it but it wouldn't restart due to those apps not responding. But I could still browse finder and other things. So I held the power button until it turned off. Now it's just stuck at the grey Apple screen with the pinwheel and it keeps rebooting. It'll sit at that screen for 3-4 minutes, then reboot, and it loops. I ran the Apple diagnostics and it gave me a memory error. But I'm assuming this is because it isn't genuine Apple RAM. I plan on installing the old RAM tomorrow to see what happens. Anyone have any ideas on why? I know my Powerbook freaked out sometimes when it was hard powered off due to the HD not parking. Letting it sit for a while always fixed it.