I just got the 2.20 update yesterday and I played COD4 fine after that.
After a few hours, I noticed the sound was getting a little weird, like someone's turning the volume knob up and down constantly. After the game ended, all I get is a black screen, which forces me to reset via PS Button. Then the PS3 wouldn't even recognize the disc.
However, after leaving the PS3 off for about 30 minutes, everything was fine again for about 1 minute, then I get the same problem. Then I leave it alone for an hour, and again, everything became fine for a little longer until it blacks out.
I left it off for the rest of the day, around 6 hours, and I got to play two whole matches! Yes, two! Until of course, it died again.
I've tested out a blueray DVD and other games, and they have the same problem as COD4, but normal DVD's still play (I haven't tested PS2 games yet).
So now I'm not sure whether my blueray laser is dead or not, because it still plays only after a long period of leaving the PS3 off. It's like a slowly charging ipod, the longer I leave it off, the longer I can play.
Just wondering if anyone had this problem, and how they managed to fix it short of sending it back in a coffin.
BTW, it only freezes when info is being loaded off the disc. I can go around the menus and join lobbies and such, but only while actually loading a map does it freeze.