Can anyone give me an idea why this might be occurring (see below)? 
Mandrake Linux 9.2, su'ed to the amanda user, all config files seem to
be set up OK, using chg-zd-mtx, tapetype set to the pv120t-dds4 found on
the faq-o-matic site, Dell PowerVault 120T AutoLoader with DDS-4 tapes. 
I am attempting to populate the tapelist (already "touched" the file). 
After I get this error, running mt -f /dev/nst0 status also gives me
Input/output error.  If I then unload the tape using mtx -f /dev/sg5
unload, I can reload the tape using mtx -f /dev/sg5 load 1 and mt -f
/dev/nst0 status works fine.  I attempt to run amlabel again, and the
whole thing starts over again.

-bash-2.05b$ /usr/amanda/sbin/amlabel sunday amanda001 slot 1
labeling tape in slot 1 (/dev/nst0):
rewinding, reading label, reading label: Input/output error
rewinding, writing label amanda001
amlabel: writing endmark: Input/output error

Thanks,

Frazier.