We just noticed this:
root:backup02 $PWD > grep 000131 log_1021953600
1022023724 1 132 16 backup02 114397 0 0 20app1 bptm read error on media id 
000131, drive index 3, reading header block, I/O error
1022024197 1 132 16 backup02 114399 0 0 wapcuse01aa0003 bptm read error on 
media id 000131, drive index 2, reading header block, I/O error
1022025675 1 132 16 backup02 114401 0 0 wapcuwg01bb0003 bptm read error on 
media id 000131, drive index 0, reading header block, I/O error
1022025676 1 132 8 backup02 114401 0 0 wapcuwg01bb0003 bptm FREEZING media id 
000131, it has had at least 3 errors in the last 12 hour(s)

Is it possible the volume catalog is screwed up?  How could we be looking for
the same tape on 3 different drives?

Is there a way to recreate the volume database without affecting all our
previous backups?

Thanks again.