Hi, I bought an external blu ray drive for my mini a few days ago. I tested it out and copied 1 of my films to the hdd using makemkv. I tried watching the film last night to see if it copied ok, and about half way through the film, my mini completely froze!. (had to hold the power button on the back until it turned off). Then when my mini was up and running again, I thought maybe it was because of the film being in mkv, so I tried converting it using handbrake. Well after around 20% converted, my mini froze again... Today I left my mini for awhile while I ate my dinner, came back, and it was still working fine, but when I moved my mouse to stop the screensaver, my mini yet again froze! I know watching large mkv files gives the cpu a workout, and it was running at around 90c. But my mini when using the screensaver usually runs around 55-60c. So I guess that rules out overheating? I wondered if it was my RAM, so I tried out memtest, I only ran it through all the tests once, because istat was saying my cpu and RAM were at 72c and the fans were going crazy!, but the RAM passed all the tests. When I start up my mini after it freezing, it doesn't say anything about a kernel panic or anything. So I'm out of ideas. Anyway, heres my mini's info: Processor: 2.7 GHz Intel Core i7 Memory: 8 GB 1333 MHz DDR3 Software: Mac OS X Lion 10.7.2 (11C74) Graphics: AMD Radeon HD 6630M 256 MB The hdd is just the basic very slow 500gb hdd that the mid minis come with.