it only feels a lil warm when it locks so its leaning towards DVD-Rom. maybe try cleaning the lense? I havent used it for awhile (2 months or so)till I bought Halo 3. Sounds like the disc is still spinning when it locks.
Actually, the freezing of games can be a sign of the xbox going bad. Mine randomly started freezing for a few weeks then I restarted it one time and got the 3 RRoD.
The power brick should be plugged straight into the wall as well, could be another reason some fail as what I was told.