Here's a strange one ... My Comedy Central recordings on my master backend/frontend have no sound when I play it on the same machine. These are recorded with a PVR 350. Other TV channels have sound. If I watch the Comedy Central recordings on another frontend, I can hear the sound just fine. If I record Comedy Central on another tuner, I can hear the sound just fine on the master.

Does anyone know why a particular channel might not have sound on only one particular frontend?