The saga continues so here's the update.

After much machination we cabled the drives directly to SCSI rather than the
through the SAN Data Gateway and voila, we were able to label and write to
and read from tapes.  So apparently we have some compatibility issue between
the driver and the drives, perhaps in the gateway.  There have been some
documented gothchas with firmware levels, but that doesn't look like our
problem.  Tomorrow we shorten the SCSI cables from 25m to something much
shorter and cross our fingers.

Await further updates.  I'll make the damn thing work.  The only question is
how long will it take.

Thanks,

Kelly