I see you have multiple posts for this, one of them being an idea.
The WDTV Hub cannot play DTS-HD, it will downcode it to DTS only.
I think it was something to do with licensing, there are a few threads on the subject here.
http://community.wdc.com/t5/WD-TV-Live-Hub-General/DTS-HD-audio-Yes-No/m-p/75796/highlight/true#M235