Issue is solved, turned out to be 2 simple PEBKEC issues:
- When I did my clean installs I simply reinstalled all of my programs from a thumb drive, including an old version of Password Safe, assuming that they would update themselves on first run; however, PS is not self-updating (user has to go to Help->About a click a link to get it to check for updates or simply stay on top of PS news).
- I realized that the Challenge-Response Tester requires you to touch the gold button on the YubiKey during testing in order to supply the response.
So, I can report that the YubiKeys functioned normally in all tests, and that they work fine in the current version of Password Safe, which as of this post is V3.39.01.
Two remaining questions:
- You mentioned using Slot 2 -- is there a reason to use this instead of Slot 1 for this application?
- When I created the new Password Safe, PS reported that the Yubikey was not "initialized" but Google turns up zero meaningful results about "Yubikey initialization." Any idea what this means?
In any case, thank you very much for your help!