Can choose 5.1 in Audition CS6 for monitoring, but not in Premiere Pro CS6

Question

System: Z820, Win 7  Ultimate x64
Audio: Creative SoundBlaster Recon3D PCIe, Altec Lansing 5.1 speaker system
SW: Master Collection CS6
I've been using Premiere Pro CS6 for a while now, but only for stereo video projects. I recently started working on a short film and needed 5.1 Surround Sound as well. I created a 5.1 surround track in Au, and have been able to monitor the sound and surround panning effects in Au during development. Here are the Audio and Channel Mapping settings I used to get my 5.1 to work so I could monitor it:
As can be seen, I've chosen the default MME Device Class here, and all seems well. I have 6 channels identified and mapped to the right corners. I've also confirmed my Master Track in Au is 5.1 Surround. I exported a 5.1 WAV and imported it into Pr, into a 5.1 surround session, confirming that both the track where the WAV file landed and the Master are both 6 channels (and although the order is displayed differently, the content correctly mapped from Au into Pr).
Now, my fun began. When I monitor the audio in Pr, I hear only Stereo. So, I check my channel mapping in Pr, as shown below:
As can be seen here as well, I've chosen the 'default' Premiere Pro WDM Sound. I've learned that WDM is a newer version of MME and encapsulates all the functionality of MME. I'm not sure why Au uses MME and Pr uses WDM. However, as shown, with WDM chosen, I only have 2 channels in the mapping dialog to work with, not the 6 I have (and had in Au). Nothing I can do will produce those other four channels.
As seen in the drop down captured in the above screen grab, I also have ASIO4ALL installed, but that too only shows 2 channels in both Pr and Au. Interestingly, when I hover the mouse over the speaker selection in the ASIO4ALL control panel, it only indicates there are 2 channels (but indicates that there are 6 INPUT channels). The Creative SBZ Series ASIO option is no better, providing only 2 channels.
So, I was off to check my system settings, which are all shown below:
As seen above, Windows knows there is 5.1 surround on the system, and the Test available  in the bottom left dialog proves that each speaker is configured and working correctly. Audition also knows there is 5.1 available on my system and uses it correctly as described earlier. However, Pr refuses to recognize this and as a result I am unable to monitor any 5.1 surround projects on my system. If neither Au nor Pr worked, then I'd mark it down as Sound Card or Driver issues, but since one Adobe product uses the system audio correctly, and the other doesn't, it leads me to believe that it is Pr who is at fault.
So, my question is this: Why won't Pr recognize my 6 output channels like Au does?
Any advice would be appreciated.
Cheers,
Shane

Answer 1

ryclark, I believe you are correct in that Au uses MME while Pr uses WDM, but both MME and WDM (which, according to the Microsoft specification, encapsulates ALL of the MME capabilities, and expands on them) are 5.1 capable. I can play my export from Au as a 6 channel interleaved WAV file as well as an AC3 conversion  of that same file in both VLC and Windows Media Player and get the same 5.1 channel surround sound field I do from Au.
After more research, I'm beginning to think this might be a result of the fact that Pr is 64 bit and Au is still 32 bit in CS5.5 and 6. I don't know if Au CC is 64 bit, but if it is, I'd be interested to know if what I am seeing is reproducible in the CC versions of Pr and Au (to eliminate the 64 bit vs 32 bit argument). Some have suggested that perhaps the standard SB driver is only 32 bit, although it 'supports' 64 bit supposedly, but maybe Pr just can't handle that 32 (faux 64) bit driver. A possibility.
Thanks for the read and response. Seems lots of people are in this boat together. You have recommended elsewhere to use an external audio interface, but just to do 5.1 monitoring (I don't do any live recording to my PC, this if for movie sound post/mixing) sounds pretty clunky. At the least, I think I'd need not only an external audio device with at least 6 channels out, but a receiver to take those outputs, and 6 new audio speakers to connect to that AVR. I currently use my computer's soundcard, as you know, and your standard 5.1 powered computer speaker system attached to that. Not the best, I know, but at this point, I'm just going for surround, but THX, so it is sufficient ;-).
Cheers,
Shane