>07/11/2001 12:50:41   ANR8301E I/O error on library FFATL04 (OP=045C6D37,
>                       SENSE=N/A, CC=00000023).

Rob - From my notes at  http://people.bu.edu/rbs/ADSM.QuickFacts :

ANR8301E I/O error on library ______ (OP=005C6D37, SENSE=N/A, CC=00000023).
        CC is the I/O completion code (some of which are documented in Appendix
        B of the Messages manual), where 23 indicates that the device does not
        exist in the library.
        Seen when the mtlib status command shows a drive as "Device available to
        Library.", but ADSM finds itself unable to actually use the drive (an
        ADSM server 'SHOW LIBR' has it avail=0).  Attempted mtlib will show:
         mtlib -l /dev/lmcp0 -m -f /dev/rmt3 -V 000081
         Mount  operation Error - Device is not in library.
        Look at the 3590 control panel: make sure that the drive is functional,
        and that the appropriate Path is Online.
        There was a defect in 3.1.x and 3.7.x Server code, affecting drives in a
        3494 library, where an UPDate DRive command without a DEVIce
        specification can cause the device number to be lost to the server.
        (See APAR IC27477)

Perhaps this is what's plaguing you.       Richard Sims, BU