[mythtv] Sound from livetv on back end, but not front end.

[hondaman]

I have a backend, and a front end.  I have both boxes output to seperate 
sound recievers (via spdif) and tvs.  The problem I'm having is that I 
can watch and hear live tv on the backend when I run myth frontend on 
it, but I cant hear live tv on the front end box.  I have a picture, but 
no sound.  Sound works for movies on the frontend, however.

Any ideas what could be wrong?