Ultraviolet Digatal copy of a movie jolts a lot and is un-watchable?

So I just bought a move on a bluray disk and it said it came with a digital copy and I thought I would try it out. I installed this fixster and ultraviolet thing and got the accounts and everything. I downloaded the movie so i could watch it with no internet connection. But the movie is un- watchable! Every few seconds it jolts and in general is pretty bad quality. Did I do something wrong? Is there anyway to fix this?

Thank you :)