SonarX1 Surround basic principles

This is a basic "am I missing the point" question I have X1 Producer on Win7 64 with usb to M-audio fast track pro, then from Spdif coax out to a AV 5.1 receiver (Yamaha RX-V371) which can decode DTS/Pro logic. I have a surround bus which outputs a nice clean signal and I can move the panner for left and right front and center, there is LFE output and a signal to the 5.1 surround speakers. But, this is not controllable in the way I thought it would be. I assumed I should be able to control the panning exactly to any speaker but no matter which set up I use (ie SMPTE/ITU) and whichever decoder I set on the receiver I just get basic left right and a LFE signal through one of the fronts. I only seem to be able to select "M-Audio USB ASIO S/PDIF 3/4 Fast Track Pro (1)" or/and "M-Audio USB ASIO S/PDIF 3/4 Fast Track Pro (2)" which I think sends the full signal to the single coax output on the FTP, I assumed the AV receiver was meant to decode that single signal. Is it that I can't do this live? That seems wrong... The decoder works fine otherwise. I feel like I'm expecting this set up to do something it can't but can't see my mistake. Any advice/walkthrough/tutorial/idiot link appreciated. Z

Thanks very much; I'll stop trying... thought I was missing the point.

There are more people with a computer and a surround kit attached then people with a dvd/bluray unit and a 5.1 receiver.

I doubt that is true. Most people use surround sound when they are watching their TV and not their computer.