I was using my MBP today with a external monitor attached, and suddenly a "shadow" swept across the screen from top to bottom. A window popped up basically saying in a few different languages: "There is a problem, you must hold the power button and turn off your computer". When I turned it back on, an error report screen popped up and I reported it to Apple. I was only running Safari with 2 tabs opened, One on MacRumors the other loading Gizmodo. Should this occurrence be something that I should worry about? HELP!