Quicktime movie freezing

I just installed Lion 10.7.3 on my mac mini that is hooked to my HDTV (Samsung) that I would play movies from that I have ripped from our DVD collection. They played fine with Snow Leopard, but now when I try to play them they freeze and will not advance. The movie starts but in less than a second it is frozen and the "Play" symbol is showing. If I click on it, it will just flash and revert back to the Play symbol. I can play the movies using VLC but wondered if anyone else is having an issue like this?

I also installed Front Row and inserted the correct files in the library so that it would open and operate. I can play the movies in it but they will freeze randomly for a second or two with the audio continuing. I changed it to open in 32 bit mode, but that didn't help.