PS3 DG720 HDMI Audio

[chyeahchyeah]

So I already know that this is a stupid question, but I've been searching the forums and all the answers I am finding are either above my head or not directly related to my concern. So sorry in advance if I'm littering the board with duplicate threads.

I just bought a DG720 as a receiver for, among other things, my Playstation 3. However when I connect the system via HDMI I only get video, and the only way I can get audio from my receiver is if I use an optical cable or an analogue one. While this isn't the worst thing to ever happen to a person I am really hoping to eliminate the clutter and use one cable for all of these connections. I thought that I would be able to go through the Playstation 3 settings and manually change the audio output but when I choose "automatic" in the setting it tells me "This HDMI device cannot be used for audio output," so I am totally out of ideas. Has anyone encountered this previously? I am assuming that it is a ridiculously simplistic problem and I am just not intelligent enough to understand what to do.

Anyway, if anyone could help I would really appreciate it.