Is anyone else experiencing trouble playing video in itunes? Video intermittenly pause and plays without audio? Video used to play fine this problem only started since the last version of itunes, version 7. Just updated to v. 11 still having same probs

Is anyone else experiencing trouble playing video in itunes? Video intermittenly pauses and also plays with not audio. Video used to play fine. This problem only started since I upgraded to version 7. I have not used itunes since then because I couldn't watch anything without experiencing these problems. I was waiting for the next version to come out and hoped it would fix the problems I was having, but no such luck. I just upgraded to the latest version, version 11 and I'm still having the same problems. Anyone else having these same issues and if so, any solutions?