The UAD Firewire Satellite now appears to be no longer in the circuit, but I am going to worry about that later. Maybe *much* later...
On reflection, I see how this happened. The tech at the repair shop saw the Thunderbolt ports and connected the unit that way, because his test rig had Thunderbolt. When that happens, the unit automatically asks you about installing the "newer" firmware and deactivates the Firewire ports.
It's a bit of a design problem that you have to *have* a Thunderbolt-equipped computer to downlevel the firmware, but probably not a common one. I expect to switch over to Thunderbolt later this year, but first I have to build a new computer...