Sybase Backup - Add backup specification Error 53


I have a strange problem, but cannot figure out what's the deal.

During adding a backup specification for Sybase I get the following error and cannot save this spec:

The database reported error while performing requested operation.
Process exit code: 53, Signal: 0
ISql error

On client side I can check with the perl script "util_sybase" and get return code zero

perl -config SID D:\sybase\SID D:\sybase\SID\OCS-16_0\bin\isql.exe sapsa "12345"

Even on server and on client side I can't find details in log that would help.

Any idea how I can extend tracing for adding backup specs to get the needed details what's wrong?

BTW: on another backup server, same DP version 9.09, I can add a Sybase backup spec (for another database), so I would think it's a client problem.

Thank in advance for any help!

Best regards,