Quicktime is 'choppy' when playing MP4's
I just recently purchased an HD camcorder and am having trouble playing an MP4 file in Quicktime. Windows Media player wont play the format at all and while I have no problem using Quicktime (I actually like the player better) the playback is 'choppy' and 'jerky'. I have no problem with audio only the video.....and while the picture is sharp and clear, it almost appears to 'skip' if that makes any sense. Any help or suggestions would be appreciated......I want to enjoy my camera. Thanks!!!
Windows Vista