First go to
and check out if your media sets are following the guidelines shown.
The application default setings may contribute to the problem. Have you made any changes to the job or media set definitions (particularly the append period or the media set name)? Check the following - had a similar problem after someone made changes for a backup, but didn't document what they did.
1. Media set properties, append period set it to "INFINITE-ALLOW APPEND if some other period has been selected.
2. Click on TOOLS, OPTIONS, MEDIA OVERWRITE and set the Media overwrite protection to FULL. Also click on the job, edit properties, on the ADVANCED tab in the BACKUP OPEN FILES just check YES, WITH A LOCK.
I assume that the tapes have had backup jobs written to them previously. You could also remove the tape from the media set, quick erase, re-label, and place back into the media set. This will ensure a clean start with the media (the media stats will be retained because they are tied to the media ID).
If you have version 7.3, build 2575 you may need to install the SPANFIX.EXE patch as well.