Maximum PC

I recently purchased an XFX 6850 for my home theater pc. I wanted this card because I read it was good for gaming and great for video and Blu-Ray. I wanted a video and sound solution for simplicity. Well I am having some issues with the sound portion.
After installing the card and the drivers I go to Windows Sound in the control panel and when I click on HDMI audio, I only see 2 speakers. This card outputs via HDMI to my Onkio 7.1 Receiver.
While watching movies and Blu-Ray, I hear all 8 channels. However when I play games and listen to other content I only get stereo sound! I installed Dirt 2 Demo, and it looks great, but since Windows is only reporting to the game the computer has 2 speakers, then the game only outputs to the pair. How do I get Windows to recognize all 8 channels??? Is there some setup I am missing to modify the sound setup in the CCC?
HTPC is:
XFX 6850 w/ Latest Catalyst drivers
Windows 7 Ult. x64
Asus P5Q Pro
Intel q9550
Happauge Tuners x3
ATI Tuner PCIe
Seagate hard drives x9
Intel SSD G1 80GB
3Ware SATA RAID Controller 9650

It's a confusing mess I wish they'd all clarify really. The video card is not a sound card and has no sound creating area of it on the board. What it has is a processor that passes along signals from other points; with the best intent of 1:1. What you're actually facing is onboard sourced audio, it's passing it to the bus, up the card and it's processor, and out the back via the HDMI mixed signal.

I'd suggest to skip Windows sound and dealing with the driver set for the actual processing chip on your board (Realtek ALC1200). Set it to 5.1 and go from there.