I'll just add a note here

I just completed labeling and checking in 640 new 3590K tapes into a new
3494.

Every label operation reported an I/O error both in TSM and in the errpt on
AIX.  However; the tapes were in fact labeled and checked in.  I have used
some of them and there doesn't seem to be a problem.  I don't like the fact
that I get the errors.

Knowing that others are experiencing similar difficulties is of some
comfort.  However; I would like to know why the errors are being reported in
the first place.