I have a Tivo 3 that's been fine recording SD PBS shows, and the sound from BR and DVD is also fine. But I've had to delete a bunch of HD PBS shows from the Tivo because the center channel is missing, or almost missing. You hear the music, effects, etc. but barely hear any dialog or narration.
What would you check? Could it be a problem at the station?
(Tivo's getting OTA from a rooftop antenna. It's connected to a Yamaha 3800 via HDMI, and Yamaha is connected to TV via HDMI)