I'm seeing this as well.

I'm not familiar with the internals of amanda and have been doing some
hacking....

If I try and run taper interactively.. and give a START-TAPER command:

$ /usr/lib/amanda/taper  DailySet1
... debug buffer stuff ommitted ...
taper> START-TAPER 20060425
changer: opening pipe to: /usr/libexec/chg-zd-mtx -info
changer: got exit: 0 str: 1 1 1
changer_query: changer return was 1 1
changer_query: searchable = 0
changer_find: looking for Daily102 changer is searchable = 0
changer: opening pipe to: /usr/libexec/chg-zd-mtx -slot current
changer: got exit: 0 str: 1 /dev/nst0
$ ( goes straight to command prompt )

If I comment out tpcchanger in amanda.conf, it works! (I get a TAPER-OK
message).

If I delete the /etc/amanda/Daily/chg-zd-mtx* status files, I can go
back to the changer again....

TAPER still doesn't write to tape though... (no error, IIRC)

For now, I'm going back to 2.4 so I can flush the holding files to
tape, then I'll reload 2.5 and start trying to troubleshoot again..

Robert