Problem streaming videos since 8.2 update

Hi, since the 8.2 update I haven't been able to either stream or download videos I made and posted to my class in iTunes U. When I tap the links, the iPad (2) freezes for a while, and then iTunes U quits and it returns to the home page. By the way, when I log out and sign in again with another account as a student, it works fine.

Any ideas/solutions?

Thanks, Tromba1