I do not know Unix, however, seems like your tape lib may not be receiving 
witdraw cmds or being confused about it, if you have lib then nsrjb -w -S 
should work, try nsrjb -HEvv to reset the lib and then try again, check 
deimon logs etc.
Make sure the devices were created correctly and there is no errors 
related to thier funtionality.
check Drive cabling, does your backups work, do the drives mount ok, how 
about drivers and SCSI\FC error logs, CDI flag on devices etc.
Start by jsrjb -HEvv first.

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