My question is: is there some technical limitation to firewire
(specifically Oxford 911 bridges) to handling large-capacity drives?
Yes. Older versions of the 911 can't use LBA48 addressing, even if you
upgrade the firmware. There are newer versions which can, of course,
and some of them may have come with pre-LBA48 firmware, in which case
they can be upgraded. So I'd check the manufacturer's website to see
if there are any firmware updates available for your FW enclosure.
Failing that, you'll have to buy a new enclosure; anything with an
Oxford 911 or greater which hasn't been in the channel for very long
should do LBA48.
