I wonder if it is possible to change the default user of yours amanda client from 'amandabackup' to 'backup' which is Debian's default for their amanda package.
Now amanda-client-3.3.0 (for Debian 6.0) claims that folders /etc/amanda and so on are owned by user backup and exits with errors.

I'd like to do that change because I have amanda server installed from Debian packages and many amanda clients also. And for now I'd like to test only your package on one server, so not willing to change all the other servers configurations.