Deselect verify media button.
***EDIT***
However, was this media used elsewhere?
Albeit this indicates differently:
9/3/2010 11:44:33 AM - expected media OT0001; found
NetBackup media
STATUS CODE 93: Backups fail with Status Code 93 - media manager found wrong tape in drive
http://seer.entsupport.symantec.com/docs/282913.htm
***EDIT #2***
Was it maybe utilised as a cold catalog tape in its previous life?
How to recycle offline cold catalog backup media tape for new NetBackup policy backups
http://seer.entsupport.symantec.com/docs/295233.htm