[Dovecot] Dovecot doesn't read users and passwords from config files

[Marco Fioretti]

Greetings,

I am setting up Dovecot 1.0.15 on my home Fedora Core 8 pc ONLY to
access my mail archives across several mail clients. No access from
the internet is possible or needed here.

I cannot log in with any client, the login always fails. The reason,
as I understand, is that when dovecot starts it doesn't read any user
name from the userdb file, so when I try to login it doesn't recognize
my name and so doesn't even try to verify the password:

maillog excerpt:

Aug  3 00:06:11 polaris dovecot: Dovecot v1.0.15 starting up
Aug  3 00:06:11 polaris dovecot: auth(default): passwd-file /etc/local_dovecot_passwords: Read 0 users
Aug  3 00:06:11 polaris dovecot: auth(default): passwd-file /etc/local_dovecot_users: Read 0 users
Aug  3 00:06:12 polaris dovecot: auth(default): new auth connection: pid=5150
Aug  3 00:06:12 polaris dovecot: auth(default): new auth connection: pid=5148
Aug  3 00:06:12 polaris dovecot: auth(default): new auth connection: pid=5149
Aug  3 00:06:26 polaris dovecot: auth(default): client in: AUTH#0111#011PLAIN#011service=IMAP#011secured#011lip=127.0.0.1#011rip=127.0.0.1#011resp=AG1hcmNvAGdpZ2V0dG8=
Aug  3 00:06:26 polaris dovecot: auth(default): passwd-file(marco,127.0.0.1): lookup: user=marco file=/etc/local_dovecot_passwords
Aug  3 00:06:26 polaris dovecot: auth(default): passwd-file(marco,127.0.0.1): unknown user
Aug  3 00:06:27 polaris dovecot: auth(default): client out: FAIL#0111#011user=marco
Aug  3 00:06:27 polaris dovecot: imap-login: Disconnected: user=<marco>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, secured


the dovecot.conf file, purged by comments, is below. What am I
missing?

TIA,
		Marco
##############################################################

protocols = imap

listen = localhost:143
mail_location = maildir:/home/marco/.MAIL/home_imap/

protocol imap {
}

protocol pop3 {
}

protocol lda {
  postmaster_address = postmaster at example.com
}

auth_debug = yes
auth_debug_passwords = yes

auth default {
  mechanisms = plain login
  passdb passwd-file {
    args = /etc/local_dovecot_passwords
  }
  userdb passwd-file {
    args = /etc/local_dovecot_users
  }
  user = root
}
dict {
}
plugin {
}

###################################################


the local_dovecot_passwords and local_dovecot_users files are
identical, and have permission 644:
marco:{PLAIN}thepassword:500:500::/home/marco/.MAIL/home_imap/

-- 
Reality is for those who lack imagination