Hi there. I don't know whether this should be in Mac OS X or in here, but I've just posted it here in the end. I've been getting this 4 times in a row and now my concern is growing. I have an MBP as per my signature. Twice yesterday and twice today, my machine has just stopped responding. There is no spinning beach ball, there is no indication or warning whatsoever. It just stops working. Even the mouse stops. I haven't used it as a laptop for the past 3 days, so I don't know whether or not it only happens when I'm using it in clamshell mode (which I was, all 4 times) Now what I have had running common to all 4 incidents are iTunes playing a song, Safari (1 window, containing 7/8 tabs) MSN Messenger. Earlier on I had Preview open and also Transmission, but that wasn't on in the first three times. Now I don't exactly remember what triggered it in the previous times, but earlier on I just used cmd-W to close a tab in Safari, and my whole system crashed. iTunes began looping the last 0.5 seconds of music over and over. There seemed to be nothing I could do except force shutdown. Anyone?