First of all I didn't know that tape drives could have "gooey
interfaces."
Seriously, I have had problems in the past when the tape drive was
active when the system came down. Upon rebooting the device was not
recognized. I had to go in and delete the device and re-add it in
SYSGEN, cut another CSLT and then boot from tape using the UPDATE CONFIG
option at the ISL prompt.
I don't know if this is similar or not but I hope this helps.