Thanks to all you forumers, I have successfully completed my HTPC and have it correctly hooked up to receiver -> TV. Everything is playing wonderfully and correctly except HD audio on my receiver is not lighting up.
I got my blu ray drive and have made a few copies of my movie, making sure to select the DTS-HD tracks if applicable. When I play the tracks in XBMC, I go to Audio Settings and it shows that it is displaying DTS-HD but when I look at my receiver, it just says DTS. Is there something I am missing here? I am using the AMD HDMI sound driver (as I have a ATI 5770 graphics card) set to 5.1 and it says it supports DTS-HD and True HD.
The file is a 1080p MKV ripped with MakeMkv. I have the Onkyo 609 and the PC hooked directly into the input in the receiver. I know my receiver supports it because I've seen the option before on blu ray movies. Also, I can see the "HD" next to the DTS glow greyed out.
Thanks for your help!