iMore

the podcast videos are not running right in iTunes for me.They freeze up after just a bit, and won't restart; or the message comes up "movie cannot be played". I rented a video through iTunes, and got halfway through, then it froze also. I couldn't make it work trying to jump a chapter ahead, or restarting the movie, it always froze in the same spot. however, my YouTube videos are running just fine! help please? is it a setting, or is iTunes notorious for glitching video?