If I have a tape that according to the available_media_report has been
marked as FULL, but the images on media report returns no information, a
vmquery -m shows no expiration date, and a media contents report shows only
one image that has not yet expired, what do I make of this?  

I would say keep it in the library until the expiration date shown on the
media contents report passes, but according to the images on media report
there isn't an image that NetBackup knows about anyway, and if I cd to the
/db/images/client-name/epoch_directory there is no image matching what is
displayed on the media contents report.

Should I just manually expire the tape and put it back in the scratch volume
pool?  Or should I keep it until the expiration date?  Any idea what could
cause this? 

Thanks,
Taylor