[GrimGriefer]

Thought I'd post a weird bug I have noticed with OpenELEC that I have also posted to their forums.

Setup
1 x Shuttle XS35GTV2 (nVidia ION2) -> Onkyo HTX22HDX

Also of interest, I also have another setup of 1 x Shuttle XS35GTV2 (nVidia ION2) -> Onkyo HTX22HD (older model) and that works fine with for HD audio streams using whichever release candidate of OpenELEC.

Sounds like it may be a handshake problem between the Shuttle and the Onkyo. Have you tried extracting a custom EDID and adding it to your xorg.conf? Checkout the Config EDID nVidia wiki article on OpenELEC

No luck I'm afraid Vicbitter. I extracted the EDID using both 2.99.2 and 2.99.5 of OpenELEC without any problems. Made the necessary changes to the newly create xorg.conf and checked they were working by changing the display resolution to force 720p (which it did) but again no HD audio on anything above version 2.99.2.