I'm not sure if this is an all around problem with every xbox version, but on the sidequest 'Finding Dustil' once you get to Korriban and start talking to him, if you kill him then afterwards everything is messed up. You can't interact with anybody or check his remains or anything, and the only thing left to do is restart the game cause you can't even load up your old spot.
I've already played two different Xbox's with two different Kotor games and this glitch has happened both times.
have you tried NOT killing dustil?
I'm just saying that if you try and kill him the game messes up, that's all.