Yeah, the gold image was not successful either. I always assume I'm in the wrong, so I'm going to look at this again.
You mentioned you do USB Redirection, but not SmartCard redirection? Any reason why?
There's still the possibility that for whatever reason the SC you are using or the Zero clients are unable to work in this fashion. So it's not necessarily your fault so to say.
I'm not 100% sure why, but when I had SC redirection enabled, it stopped working. My best guess is that the reason is that we bridge the SC devices. This however is necessary from what I've read, at least for Teradici clients.
Have you had this working in any constellation you've tried so far? Maybe a full clone of your GM?