Ugh, I feel your pain. People who don't pull their own weight are the worst, and I'm glad you managed to find a solution to deal with him.
I'm working with a guy in my clinical rotations at my University, and he is such a dumbass who doesn't do any work (just barely enough to get by). On top of that, he has a rotten personality, and definitely not the kind of guy you could rely on to cover your back. He might as well be invisible (except he's not, which is worse!)
In my situation, I brought the issue to my professor and asked for us to separate our work instead of doing it together, because he sure as hell doesn't deserve my grade.
It's funny how everyone in my class feels sorry for me for getting stuck with him, but no one wants to take the bullet either. =_=