I've had DirecTV hooked up to the Sanyo for several months now without any problems.
Today I added a Sony HTSS370 Home Theater 5.1 and the sound works, but there's no picture. Everything is hooked up via HDMI from the satellite receiver to the Sony to the Sanyo. The HDTV reports no signal, but if I go straight from the D-TV to the HDTV the picture returns.
Edit: I started this thread but thought better about one of the HDMI cables that was on the thin side (receiver > TV) and swapped it out with another I had that ran from my laptop to the HDTV in another room. The picture came on immediately.
What's odd is the thinner HDMI cable works fine running from an upscaling DVD player and to the Sony home theater before displaying on the Sanyo TV.
Anyway, I figured I'd go through with the post in case another had a similar problem and a possible answer.