>>This is the same job that runs daily, not different jobs?
Yes, this is the same job.
>>if the media set of a mounted tape volume is different than the media set called for by a job, BackupExec cannot append
This is same media set used by the first (successful) job already on the tape.
I've discovered and applied SP1, but it corrupted the database. In short, I've had to remove and reinstall BE. Now I'm starting all over again.