Problems with HP Ultrium 1760 SAS


I’m useing a new HP Ultrium 1760 SAS tape drive with a Adaptec 1405 controller together with open source software Bacula.
Backup and restore work well but smartctl always show errors:

# smartctl -H -l error /dev/nst0
smartctl 5.39.1 2010-01-28 r3054 [x86_64-unknown-linux-gnu] (openSUSE RPM)
Copyright (C) 2002-10 by Bruce Allen,

TapeAlert: OK

Error counter log:
           Errors Corrected by           Total   Correction     Gigabytes    Total
               ECC          rereads/    errors   algorithm      processed    uncorrected
           fast | delayed   rewrites  corrected  invocations   [10^9 bytes]  errors
read:        657        0         0         0        657          0.000           0
write:       691        0         0         0       1081          0.000           0

I tried tar as well, which also shows errors.

The tape Hardware is ok. I checked it with HP. HP only supports SUSE Linux Enterprise Server.

My questions:
Is anybody using HP Ultrium SAS tape with OpenSUSE?
Anybody has an idea what could cause the errors?
Anybody had a similar problem?

I use OpenSUSE 11.3 with all actual patches.