MTV3000 playback issue

I am having problem viewing recorded programmes with my MTV3000.  The unit plays the recorded programme just fine in the beginning, but then all of a sudden the playback would get stuck at certain point of the programme. Stopping the playback and resume play does not resolve the problem. I would have to fast forward beyond that point in order to resume playback. Has anyone experienced this?

Forgot to mention my MTV3000 is connected to a Buffalo 640 GB external hard disk.