What OS and Motherboard are you using. I recently had issues playing DTS-MA and Dolby TrueHD on system. Turned out it was the Microsoft HD audio driver that was the problem. I uninstalled it and installed the specific one for my motherboard and all was OK.
You can do a simple check Maid by going into Control Panel then Sound. Select the device that does your HDMI sound then Supported Formats. If it doesn't say DTS-MA or Dolby TrueHD and you know that your amp supports that format then the driver is screwed up.
Did you rip to MKV yourself and from what source. Your image from media info shows DTS-MA as the included audio. If your amp doesn't support this but does support normal lossy DTS then it should still play, you just won't get the lossless version of the track but your amp needs to support DTS and the sound control panel needs to say DTS as a supported format.
John
Edited: Just re-read that your using a 2 chan Stereo to output the files to. The file you have doesn't have any 2 chan audio so you will not be able to bitstream it. You will need to use JRiver internal audio engine to decode and output 2 chan audio.