I had a couple scary moments with my 360 this week, when i put in NCAA 08, it came up with a pink screen full of japanese lettering, with a flashing "To play this disc, insert it into an XBOX 360 Console" message. So far, everything is good, though.
That happened to me once with COD4. I was in the middle of a game online and accidentally hit the eject button and that screen popped up. Everything worked fine after I turned it off and back on though.
