Receiver problem (kinda long)

[bazookaman]

I have a Sony STR-DE875 Receiver to which I have connected (via optical input) my eyehome. I have the "soundfield" for that input set to Auto Format Decode. Meaning it will adjust automagially to the source. If its stereo, it sets to stereo, if its 5.1 blah bla blah. So anyway, sometimes when I'm watching the eyehome the receiver will "click". The click being the small mechanical sound it makes when you switch soundfields for example. I.e. its a normal sound. Anyway, its makes this sound seemingly at random. And sometimes when it does, my audio goes kaput. Not completely really. Its as if I've lost a couple channels of my 5.1 signal. I can switch it to stereo and all the sound is there. But if i leave it in AFD, I can maybe hear the soundtrack to a movie but none of the voices. I would imagine its the center channel cutting out as its mostly the voices I lose. Like i said, switching to stereo makes everything come back...albeit in stereo. And turning the receiver on and off a couple times usually rectifies the situation. So i guess I'm wondering if this is most likely some kind of internal electronic problem? The receiver is several years old so I'll probably look into a new one if it completely breaks.

[Doc]

Total out of my butt uneducated guess:

Maybe it's a Dolby Pro Logic source?

Pro Logic encodes the multi-channel mix into a regular stereo mix so that if the receiver can't decode it you'll still get stereo. If the Elgato unit isn't passing a clean signal or if the receiver is having trouble decoding it, that might explain the trouble.

Dunno what kind of audio signal the EyeHome passes, but it might be worth looking into.