I am trying to bitstream my media to the Pioneer Receiver.
1) Exactly WHAT Media are you trying to get to the Pioneer?
2) What Software Program do you use for this Media?
3) After Contacting your MOBO manufacturer and turning on HD Audio:
a) How were you instructed to do this, BIOS?
b) Option to see HDMI Output?
With my HTPC when I right click on the Speaker icon in the task bar, I have an option of:
"Realtek HDMI Output" and under that it states: "ATI HDMI Audio-Ready"
It bothers me that you do not see an option for HD HDMI Audio Output!
Just "Digital Output"
4) When you are playing this "Media" do you see a 5.1 Incoming Signal in the Audio Signal box on the front of the Pioneer?
This is shown on page 9 of the OP Manual, item # 2 over the display at the top of the page and then # 2 below, "Program Format Indicators"
If you are seeing L-C-R SL/SR LFE then your pioneer IS getting the necessary Format Input and you need to re-check the Audio Settings in your HTPC.
If you DO NOT see L-C-R SL/SR LFE then there is a problem with the HTPC not putting out the Surround Format.
Both Scenario's are pointing to your HTPC and ALL of today's receiver's would display the same thing.
Either you can find the correct settings or need to make another call to your MOBO Manufacturer or check the Software that works with your MOBO and it's specific settings.