I can't help you there. While I use (and maintain) tob and afio, I never use muti-volume backups as I do them off-line anyway. I just define my backup "volumes" such that they will fit on one 170 MB tape. That holds /etc, /home and /usr/local, which is all I need.
-- Dirk Eddelb"uttel http://qed.econ.queensu.ca/~edd