Chronology:
Fresh install of OSX 10.7.5 (all latest updates)
Updated A4 firmware to 1.21 as bundled with OB 1.0.0.0
Switched on Overbridge mode in A4 settings
Rebooted A4 a couple of times (for good measure)
Installed OB 1.0.0.0, rebooted
Connected the A4 via the USB cable supplied with my A4
no hubs
no other devices
connected directly to the powered port
A4 is recognized in system profiler (see dump)
Nothing is recognized in the OB control panel.
Reinstalled OB a couple of times.
Tried 2 other USB cables.
Rebooted a few times.
No dice.
Ideas?