Im going into 3rd, and I have to admit, i dont really have much contact with my ex-hallsmates.
However, this is more just to a drift in interests, living arrangements and timetables than disagreements.
I got on famously with them while we lived together, and have a good chat if we meet, but alas, thats about it. I would have to say there was only one person I didnt get on with, but they were pretty much universally disliked.