Veritas 4.81 Errors

After upgrading from Windows 2000 to Windows XP, I also upgraded Veritas
Backup Exec 4.61 to 4.81. When I load my backup software, it's name is Stomp
Backup MyPC, which is powered by Veritas.

I am using a Seagate 20.0 GIG IDE TR5 Tape Backup. After the Veritas
upgrade, I did a full backup and compare on my computer. I then deleted a
file from my computer and attempted to restore it from my backup. The
restore failed and I got the following error message:

"The set requested is no longer on this media. Unable to continue this
operation."

I then tried to catalog this backup by going to Restore>Device View and
answered "Yes" to the prompt:

"Would you like to refresh the current View."

I then got the following error message:

"This media contains no backups. It cannot be cataloged. Please insert
another media to continue."

Can anyone help me resolve this problem?