it sounds to me that you most likely have a SCSI ID conflict. Change the
ID of the tape a couple times and see what happens.
Or, change the id of one or both of the hard drives. If using the jumpers,
it's figured this way
::: = 0 (three sets of empty pins)
::D = 1 (one block on right-most set of pins)
:D: = 2
:DD = 3
D:: = 4
D:D = 5
DD: = 6
DDD = 7
Hpe this helps
Lurch