S/PDIF for D531

I cannot get a digital signal out of my D531, Vista, Sigma Tel HD Audio.  Using old dongle that came with my D600.  S vid output through dongle is fine.  Set S/PDIF as default device, nothing.  Tested different DD and DTS outputs, nothing.  Set PowerDVD to output to S/PDF, nothing.  I am running the signal to a Sony STR 5300ES that I have confirmed working with the DVD player for the same S vid and COAX inputs.

 

Do I have to use a D/Dock to make this work like the manual says?  Wife has one and will be mad if I disassemble her workstation for my "experiment".

 

Any suggestions?  Thanks in advance.