DVR-MS file - playback fine for 35 minutes, then exits

I have windows 7 wtv files, converted to DVR-MS to watch on the WD TV Live over a network share. At the same point in the show, the program stops playing and exits. I found I could fast forward past the problem spot and continue (but I had to fastforward 8x or higher) - like there was a bad spot in the file - but it plays fine on Windows 7.

In the past I have seen issues where people had to FF past spots in files - any permanent resolution? Known causes?

Thanks for any advice.