yeah i had the same on my A4000T.. only with out the movie shop thing.
diavolo was a quality program, even had extras for backing up movieshop drives. ran fine with a DDS2 DAT drive (4-8Gb tapes.)
if you want faster backups / restores, have the tape drive on a seperate SCSI controller than the drives you're backing up.
e.g.
drives (fast stuff) on cyberstorm SCSI,
tape (slow stuff) on onboard/Zorro SCSI.
depending on compression settings, don't expect blindingly fast data xfer rates, even disk to disk is a bit of a nightmare, but i suspect that FFS is a bit to blame for that... :-)
oh yeah, DONT use DAT AUDIO cleaning tapes to clean your DAT DATA drive. or much pain and gnashing of teeth with prevail :-D