My Xbox started acting up today.
When I was playing MGS2HD off of a disk, it froze. When I went back to Xbox home, it gave me the "Unrecognized disk" error. Turning it off and on again a few times made it work again. An hour or so later, it froze during a Codec conversation and no amount of opening and closing the disk tray or cleaning the disk will do anything and no other disks will work either.
I am playing on a 2GB Xbox 360 Slim.