I do not need a solution (just sharing information)
Error message JV2WWX1 was sighted on the actual IBM Ultrium Tape Device (Server 2008 R2 with BackupExec R3)
I could not find out any info on this error but it appears to refer to the fact that the Tape Device needed cleaning.
Put a cleaning tape through and the tape was recognised and we were able to run a backup on the device.