All of a sudden I can no longer watch videos I have rented they will not stream

I have iPad 2 and Have had my apple Tv 2 for about a month. Everything has been working great. Rented movies on the iPad and have watched them thru my Apple TV with no problems. then yesterday I had trouble streaming, the movies will start playing on my TV then come to a stop and stay there. If I try to restart the movie the problem happens again. It does not matter if it's a rented movie or one I purchased. have not changed any settings either on iTunes library, my iPad or my computer. Any thoughts? I had one movie expire on me before I got to see it and another ne is counting down.