We have exactly the same problem.
I've just set up a Drobo with latest firmware, I used BMFU 3.0,
everything looked fine, I started a backup of two macs (both of them
running 10.6.4). One client's backup size was 180 GB, the other one's
was about 100 GB. The backup started in the evening, and when I came
in the office in the morning, both of them were still running the
backup process, but without any progress. They had backed up about 50%
of their data, but nothing happened any more.
After I cancelled the backup in order to start it again, the same
error as reported by cabegoose appeared. After starting the time
machine backup via the menu bar, you see the "BMFU donate message",
and after that, the next message shows the error "Something wrong with
the volume's CND DB, using temporary CND DB instead. Check server
messages for details. Switching to read-only mode".
Does anyone know what's the reason for that?
Thanks in advance,
Alex