Mine is persisently hard to remove.
My vmquery -m <tape>
media ID: 000123
media type: 1/2" cartridge tape 2 (14)
barcode: 000123
media description: Added by Media Manager
volume pool: NetBackup (1)
robot type: TLD - Tape Library DLT (8)
robot number: 0
robot slot: 80
robot control host: MasterSvr
volume group: 00_000_TLD
vault name: ---
vault sent date: ---
vault return date: ---
vault slot: ---
vault session id: ---
vault container id: -
created: 7/25/2008 1:11:52 PM
assigned: ---
last mounted: 7/25/2008 5:23:19 PM
first mount: 7/25/2008 1:12:29 PM
expiration date: ---
number of mounts: 3
max mounts allowed: ---
As you see there are no Status hence the command to use can't be used.