I recently had a customer bring in his iPad and we established that the unit was not tethered to the cloud. By hooking up the unit to a desktop we were able to create an Apple ID that allowed us to back up the unit, capture data, save to the desktop then we ported the info to a new iPad. Hope this helps. You have entered into one of the most frustrating problems with the new Mac security system. We will be keeping a good thought for you. Good luck to you.
trollp- Just so Im clear a recap.
You have noted that the firewire device is showing up in the System Profiler...
You have logged out then back in under different user account name...
You have zapped the Pram ( min 3 Times )
And you have reinstalled the OS. You still have a long way to go before you get to the LB.
For instance, you may have a compatibility issue with the device and your Mac ( the type would help ).
Also cabling has been know to go bad along with the ports on your firewire device and your Mac.
If the device is a drive problems can occur with the controller card. Older drives had issues with the Oxford 911 chipset. I'm afraid the list of possibilities is to great, however the LB is one of the last items on the list to suspect. For better answers, more information is required.