HDMI is a mess, and stuff like this (or the issues that created a need for this, to be more precise) doesn't help. Check out the HDMI FAQ in my sig, it may help a bit...

I am using DVI-to-DVI or HDMI-to-DVI cables for video and then using SPDIF (coaxial or optical) for audio except for DVD-A and SACD (which are coming from my Oppo 981HD via 5.1 analog).

The only times that HDMI really has an audio advantage are DVD-A/SACD (it can eliminate the 5.1 analog if both the universal disc player and the receiver or processor do HDMI v1.1+) and the new HD formats (HD-DVD and Blu-ray). For DVD, HD cable, HD satellite, and even the PS3 (as a game console) the audio you get via HDMI is the exact same thing you get via SPDIF (coax and optical).