I have a macmini late 09 and I upgraded the RAM and HDD 2 weeks ago. Suddenly today the mini froze coming out of sleep. O left it for a few minutes but still no luck. Held down the power button and it rebooted. It goes to the apple screen and stays there. I checked the hardware and there are no problems. I then booted in from the older HDD and had no problems. I checked the permissions and repaired them. The drive comes up as being okay. Anything worth trying before I put the old drive back in?