tape back up problems

[jamesghs at aol.com]

 I am trying to back up files to a tape drive.
Here is what I am doing and the errors i am getting:

#mt -f /dev/st0 status
SCSI 2 tape drive:
File number=0, block number=0, partition=0.
Tape block size 0 bytes. Density code 0x4a (no translation).
Soft error count since last status=0
General status bits on (41010000):

# mt -f /dev/st0 tell
At block 0.

# tar -cf /dev/st0 james
tar: /dev/st0: Wrote only 0 of 10240 bytes
tar: Error is not recoverable: exiting now

# mt -f /dev/st0 setblk 0
/dev/st0: Input/output error

the dmseg is:
st0: Block limits 4 - 16777212 bytes.
st0: Error with sense data: Current st09:00: sense key Aborted Command
Additional sense indicates Scsi parity error
st0: Error with sense data: Info fld=0x0, Current st09:00: sense key 
Medium Error
st0: Error on write filemark.
st0: Error with sense data: Current st09:00: sense key Aborted Command
Additional sense indicates Scsi parity error

can anyone help me? I am at a loss for what to do.