I'm happy to read this thread. Despite using Windows 7 64-bit I'm quite sure I was initially told to copy the "dtsdecoderdll.dll"-file from TMT into the sys32 folder anyhow. I had then since speculated why a film like
Baraka, sporting 24-bit/96kHz DTS HD sound, only showed 48kHz in my DAC display when being played back, and whether it meant I wasn't making full use of the DTS HD track(in 2 channels), both with regard to bit depth and sample rate. Also being that I had no way to check the actual bit depth during 2-channel playback, which still doesn't appear to be possible.
Well, it now seems I wasn't making full use of the 2 channel DTS HD sound, not that I'm necessarily making the fullest use as is; yesterday, after reading this thread, I copied the dtsdecoderdll.dll-file into the sysWOW64 folder, and wouldn't you know it - my DAC now shows 96kHz with Baraka, and most importantly the sound now appears more distinctly and clearly presented

Great.
The bottom section of the DSP, under 'source,' now also displays the right number of disc-native channels(be it 5.1(6 ch), 7.1(8 ch) or whatever) as well as seemingly correct bit depth, but whether it means I'm actually playing back in 24-bit(when natively offered) in 2 channels is not clear to me. I would guess though that 24-bit 2-ch. sound is enabled when the disc offers 24-bit.
However, my stream selection for DTS HD still only shows 1536 kbps, like it did before - shouldn't it be higher and vary, even with two channels? As far as I can tell the bit depth displayed in the upper pop-up display during playback is still not reliable/true - sometimes there's no bit depth information, and at other times it just shows 16-bit with DTS HD titles, despite the fact that a 24-bit title is playing. Some PCM and TrueHD titles on the other hand seems to be correctly displayed here.