We have had an issue with some images imported with the wrong mediaid, actually a 14 write error from db_end()
They couldn't be imported through the GUI as the mediaid was wrong, attempt gave 2067 EMM Status: Disk volume not found
The images in question couldn't be exipred as they was a part of an SLP and couldn't be cancelled from the SLP
Discovered that bpimage -deletecopy <copyno>-backupid <image> would remove the problematic image on the target server.
So the procedure became
1) Identify images with wrong media though the GUI under catalog, with Import, Mediaid<All>, <All Copies>,<All Policies>,<All Policy types>,<All Clients>
2) Delete the images with bpimage -deletecopy <copyno>-backupid <image>
3) replicate the image from the source server with nbreplicate -backupid <image> -cn 1 -rcn 1 -slp_name <SLP> if the image was still valid
4) Check with nbstlutil stlilist -U -backupid <image> that the image was managed by the SLP(s)