I think I'm just going to hook up an optical cable between the TiVo and the receiver for audio. The HDMI audio drops out as soon as you start to fast forward or reverse, so you lose a little bit when you start playing again. And the sound effects don't work properly. Plus, the TiVo doesn't output in more than 5.1, so I don't think I'd be losing anything by not using HDMI audio.

I am the Doctor, and THIS... is my SPOON!