thanks for all the replies guys.
I ended up figuring out what was wrong, it was/is the computer's USB ports. I plugged one of the Ztex into a laptop thats never been used for mining. Downloaded BFGminer and Zadig, changed the "unidentified device" driver to to WinUSB (or whatever it is), config'd BFGMiner (pool/user/pass/hardware to not use) and it worked.
This is a brand new board and virgin OS (Win7-64 SP1) install so its not like theres something there that shouldn't be. FWIW, the USB ports all work for block erupters, I had some sitting around so I plugged them in for the extra hashing power. They also seem to work for everything else I've plugged into them, just not Ztex.
Strange...
But, as I said, thanks for the replies!