[mythtv-users] Odd Compatibility Problem

[Ken Mandelberg]

I'm seeing an odd compatibility problem. This is the setup.

Machine A has backend and frontend.
Machine B has frontend
Machine C has frontend.

All recordings are mepg2, not transcoded from a HDHomerun.

A and C can play all the recordings.

B can only play the ones recorded after a certain date. The older ones 
appear in the listing but when I try to play them the machine goes black 
for a while and then goes back to the list of recordings.

I can manually scp the recordings that don't play on B over to
B, and make B play them inovked as "mythtv <filename>".

It's not the source or format of the recording, since there are 
recordings of weekly series off the same station, where the one from the 
week earlier won't play, but the one from a week later will.

Any ideas? What debug options should I try?