It seems to me like it is the mt command that doesn't work. I removed the lines in /sbin/e-smith/backup that checks if there is a tape and then rewinds it. Remove from and including the first "if" and to and including the "fi". This will remove the if/else function that gives the "no tape loaded" error. The flexbackup command seems to handle the drive well, and it also rewinds and erazes the tape.
It would be nice if someone could do a restore from such a backup, so we can be sure it works as intended.
-Lars