Backup...if you can

NTBackup on a server. Tape is full. Eject and insert brand new fresh out-of-the-package tape. NTBackup says it's unformatted; do you want to format it? Of course! Click "Yes". Message screen disappears. Window still says waiting for new media. Waiting. Waiting. Waiting. Eject media. Re-insert media. Nothing. It's taken almost ten hours so far; I don't want to blow this backup and have to start over. Idea! Stop and start Removable Storage service. Then:

The requested media failed to mount. The operation was aborted.
The operation was ended.
Backup completed on 3/1/2006 at 10:36 AM.
Directories: 3696
Files: 24976
Bytes: 18,250,089,521
Time: 9 hours, 48 minutes, and 41 seconds