HDMI is a big bucket of hurt. I have a Sony DVD/receiver and a Panasonic plasma TV. My Apple TV works great with the Panasonic but not with the Sony. The Panasonic's audio won't play through the Sony either. It's a real pity, as the Sony has some really good speakers.
The frustrating thing is, it used to work. Then it stopped. My son got it working again, but then a few weeks later it stopped again and neither of us has succeeded in getting it to work again.
Reviewing various internet forums, it seems the problem as I've described is widely experienced among this particular Sony model's unfortunate owners. So okay, that's it for Sony for me. Used to be a big fan, but they jumped the shark years ago and now they've wasted a big chunk of my change. Onkyo isn't what it used to be other, as several posts on this thread attest.
At some point when I have spare funds, I'll replace the damned thing with one by Panasonic or Pioneer.