yamaha receiver and Xonar d2 sound problem...please help

[Captain Carling]

I have been using the onboard sound from my Asus p5q deluxe to send the signals to my Yamaha DSP-AX759SE and it's been working well for some time (Media centre set up for blu-ray etc and 5.1)
It's connected via optical cable.
I thought I would treat myself and buy an Asus Xonar D2, but now I have inherited a problem as it will only play in stereo.
I've installed the latest driver, and the software control suite, and I have noticed that my receiver is showing 'straight' on the display.
Have I missed something?
Please help

 

[Captain Carling]

Ive bought the card today and I have a 7970 with hdmi. I haven't got a hdmi in the receiver.
I solved my problem by setting power dvd to stereo, then the receiver showed dts not straight

 

[Captain Carling]

Sorted, downstairs pc back to mobo optical out, and my main rig upstairs has had the Creative extreme audio removed and ive put the new one in that ha ha.
I have Creative surround speakers on the main rig so this card is doing it's job now.
Thanks for the help guys