WOOHOO! I have fixed the issue. If anyone could make heads or tails of WHY, I would appreciate it.
I had a external HD with all my pre-configured emulators on it. For whatever reason, trying to run recent mame versions (0171 and 0172)out of the H:\MAME\ folder would always result in no audio. Strangely, if I ran my old 0158 exe audio worked just fine.
I fixed it by creating a new directory, H:\MAME\test , then taking everything out of the MAME folder and moving it to the test folder. Simply nesting the files in one directory lower resolved the problem.
Prior to this, I had already noticed that there was something strange with the directory itself as I could run the same setup from a different location fine, but the moment I moved it over to my usual directory the problems occurred. I checked out all the attributes, security settings, everything on the folders, and they all are the same. There is simply no reason for it to happen that I can figure out, yet there it is, not working in that dir, but working in any other dir.