So sorry for the trouble. It sounds like you may have a clogged/slow
internet connection.
This is what I usually suggest to our Dialup/Slow internet users: When the
video player loads and you are ready to play, press play and then play/pause
right away again. You will see a little progress bar grow to the right on the player.
Once the bar is complete, the video is 100% buffered and you can play jitter free!
Hope this helps! :D