Video freezing / stuttering

I have had a WD TV live box for a couple of months and its been working great using Linux shares from my WHS 2011 server. In the last week the videos we have been watching have been freezing for a few seconds then it rapidly skips through to where it would have been if it hadn’t frozen, it also sometimes jerks through for a bit rather than actually freezing.

I have reset the box, restarted the server and also the router but its still happening, can anyone help?

P.S. The problem started happening after the box was left on all night, I don’t know if this has anything to do with the problem