tar problems using Sony AIT drive

Recently we brought up a Spectralogic 2K Tape Library that had been out of service for about 3 years to replace a DDS-4 tape drive unit as our main backup device.
Everything seemed to go fine but now I have run into a little problem.

System details:
FBSD 6.1
SpectraLogic 2K library with a Sony SDX-300 SE tape drive.
Tapes: Sony SDX 1-35C -- 35GB native capacity.
No compression.

I can write and read tapes without a problem as long as I am using a new tape. Since we have only been using this unit for a couple of months almost all of my tapes are new.

Last week I returned a tape into the rotation for the first time and wound up being unable to write all of the files required for the backup -- 22GB of data.

The tape was prepared by running mt -f /dev/sa0 erase and the mt -f /dev/sa0 rewind.
I believe this device automatically rewinds the tape when a tar completes but since I received an error code I was not sure what the tape status would be so I performed the rewind.

Here is my first pass at writing 16 files, ~22 GB, to tape:

troll2[431]# tar -f /dev/sa0 -cvv 26/
a 26
a 26/yoda.2007.01.26.07.45.23.cksum.bz2
a 26/yoda.2007.01.26.07.45.23.tar.bz2
a 26/chewy.2007.01.26.07.43.32.cksum.bz2
a 26/chewy.2007.01.26.07.43.32.tar.bz2
a 26/wssview.2007.01.26.00.10.00.tar.bz2
a 26/vpnauth.2007.01.26.00.10.00.tar.bz2
a 26/util.2007.01.26.00.10.00.tar.bz2
a 26/tdhs_main.2007.01.26.tar.bz2
a 26/siteinformer.2007.01.26.00.10.00.tar.bz2
a 26/ordersys.2007.01.26.00.10.00.tar.bz2: Write error: Operation not permittedWrite error: Operation not permittedtroll2[432]#

I thought that maybe the tape was not fully rewound so I again did
mt -f /dev/sa0 erase and
mt -f /dev/sa0 rewind.

Below is the screenshot of my second pass:

troll2[434]# tar -f /dev/sa0 -cvv 26/
a 26
a 26/yoda.2007.01.26.07.45.23.cksum.bz2
a 26/yoda.2007.01.26.07.45.23.tar.bz2
a 26/chewy.2007.01.26.07.43.32.cksum.bz2: Write error: Operation not supportedWrite error: Operation not supportedtroll2[435]#

At this point I selected a new tape, ran the backup with no problem during the write and tested the tape by performing a full read.

I again mounted the suspect tape and tried to write the files and the result was
troll2[434]# tar -f /dev/sa0 -cvv 26/
a 26
a 26/yoda.2007.01.26.07.45.23.cksum.bz2
a 26/yoda.2007.01.26.07.45.23.tar.bz2
a 26/chewy.2007.01.26.07.43.32.cksum.bz2: Write error: Operation not supportedWrite error: Operation not supportedtroll2[435]#

I have tried this a couple of more times with the same result. (What is that saying about trying the same thing over and over and expecting different results.)

I had a tape that was used to test the tape drive with when we first got the unit so I tried it. The results were identical to those posted above.

Google did not provide any help and I am now officially lost.
Can anyone point to the error of my ways?

Thanks
thumper

are you able to read old tapes?