Progressively slow video playback, fixed by refresh

Hi all,
I've tried to search for an answer and couldn't find anything, so please forgive me if this has already been dealt with.
I am running Subsonic 4.6 and trying to watch movies over LAN. The problem is that the video gets progressively slower and more choppy until about 30-45 mins into it, it gets annoying to the point of needing to do something about it. Fortunately, refresh fixes the problem and it goes back to super smooth video for another short while before it gets choppy again.
It happens across multiple client computers, so I am assuming its a server issue, but I can't figure out what it would be.
Any ideas?
Cheers
I've tried to search for an answer and couldn't find anything, so please forgive me if this has already been dealt with.
I am running Subsonic 4.6 and trying to watch movies over LAN. The problem is that the video gets progressively slower and more choppy until about 30-45 mins into it, it gets annoying to the point of needing to do something about it. Fortunately, refresh fixes the problem and it goes back to super smooth video for another short while before it gets choppy again.
It happens across multiple client computers, so I am assuming its a server issue, but I can't figure out what it would be.
Any ideas?
Cheers