No DTS on windows 7

Hi,

I'm running XBMC eden on a Dell XPS m1330 running windows 7 64 bit.
The laptop is connected via hdmi to my HDTV (PFL9664) and the TV digital audio out is connected using coax to an old reciever: Pioneer VSX D511.

I can't get the XBMC (as well as vlc and MPC) to play DTS sound.

I am certain that my system is capable of doing this because I can play it through the windows audio configuration:

1. Control panel > Sound > HDMI > Properties > Supported formats
2. Select DTS audio and click Test (sort of like in the picture below)
   
3. Surround sound is played and my receiver indicates it's DTS.
   

In XBMC > System settings i tried several configurations but none of them worked.
I ended up with the following configuration:

• Audio output: HDMI
• Speaker configuration: 5.1
• Dolby digital capable reciever: checked
• DTS capable reciever: unchecked
• Audio output device: WASAPI HDMI
  

With this configuration I can play movies with DTS but the output to the receiver is not DTS.

Any idea how can I make this work?