Adjusting the pots is really a last ditch effort and should only be done fi you have an O-scope and know what to look for and where, it doesn't take much "tweaking" to get a drive to never read a disc again.
If the thing isn't that old and still under warranty then just take it back, you could also have a bad press of your games, it does happen from time to time. If it's still under warranty I say exchange it, no point in getting into the thing if ya don't have to.
If you have the Intercooler on it remove it, I've heard of that thing causing weird lockups and such as well.
If you've had it apart and the warranty is a no go, take the case back apart and leave it open so it gets some more air, DON'T remove the fan shroud, leave it in place, but get the top off so it can get more air, not all overheating isses throw error lights and it may just be starting in on that too.