Backups failing ver 3 client vs. ver 2 server

Hello all:
Backup Server: NT 4.0 running Adsm ver. 2.1
All client servers: NT 4.0 running ADSM version 2 except for 4 high use,
critical servers that run ADSM ver. 3
Tape drive: DLT4700 Quantum
Here's my problem:
The backups on all the clients that run ADSM ver 2 have a status of
completed.  Except the 4 critical servers that run ver. 3.  They have a
status of Started.
I did a q session and 3 of them are in MediaW mode - one of them is running.
I did a q actlog and saw the following:
ANR8302E I/O error on drive TAPE0 (MT4.0.0.0) (OP=LOCATE,
                          CC=205, KEY=FF, ASC=FF, ASCQ=FF, SENSE=**NONE**,

                          Description=SCSI adapter failure).  Refer to
Appendix B
                          in the 'Messages' manual for recommended action.

06/08/1999 08:21:18      ANR0523W Transaction failed for session 117 for
node
                          ADMIN1 (WinNT) - error on output storage device.

06/08/1999 08:21:55      ANR8468I DLT volume DSM078 dismounted from drive
TAPE0
                          (MT4.0.0.0) in library AUTOLIB.


I checked the Messages and the error message is a SCSI adapter failure.
I've been getting these strange error messages for the last couple of days.
It first started out by creating write errors on the tapes.  I audited the
tapes and cleared the write errors.  None of the tapes loaded are in error
state at this time.  I was able to do a restore on a client running version
2 yesterday just fine.  I used a cleaning tape on the tape drive.  I've
re-booted the server and now I'm at my wits end.  I don't believe there is a
problem with the SCSI adapters since I'm able to do a restore, run an audit,
checkin/checkout tapes, etc.  If the SCSI adapter was the problem, shouldn't
all these processes fail?  Shouldn't ALL my backups fail?  It's strange that
only the 4 clients that run version 3 should produce these errors on the
server.  Things were running fine for the last couple of months when I was
forced to upgrade these critical servers to ver. 3 client.  What am I
missing?  I'm at my wits end at this point.  Any suggestions would be
greatly appreciated.

Thanks,

Marita Gonsalves
IS Consultant
Cary Academy
919-677-1946 x4555