yeah i've had that problem. often. blowing on the disc or inside the tray sometimes works, or just trying to load it several times over. the thing that pisses me off is that it does it to games that have no scratches or even dust on the dvd. a couple of seemingly mint games i tried to play just wouldn't fucking load at all, even after much blowing etc.
once i got this message saying something along the lines of 'system error: contact support.' after turning the thing on and off several times it worked as normal.
a couple of times the power switch flashed red... although it restarted again fine. if it does go out (although not had any problems for, oh, a couple of weeks now) fuck paying more for another one in black with 1337 or whatever written on it
pity a decent gaming pc would be like double the price