Shaking picture

Hi there,

I am expiriencing a very strange problem when playing a movie:
My movie runs perfectly until the 47 th minute, then the picture starts shaking (I mean it stops for a few milli seconds) When i stop the movie at that time and i start it again it runs good for the next 47 minutes.

If anyone can help me with this it would be greatly appreciated.

Greetings,
Sarah
Belgium