Im a dovecot newbie and need a little help with the passwd-like file auth mechanism in dovecot

I got dovecot to work fine with regular /etc/passwd file auth .. so I wanted to start using another authentication store for virtual users.

So .. I created a /etc/dovecot-passdb file and plopped in an encrypted password using md5crypt.

Here are the appropriate lines from the dovecot.conf file

auth_userdb = passwd-file /etc/dovecot-passdb auth_passdb = pam

and here is the /etc/pam.d/dovecot file #%PAM-1.0 auth required pam_nologin.so auth required pam_stack.so service=system-auth account required pam_stack.so service=system-auth session required pam_stack.so service=system-auth

So far .. no dice. Dovecot reports constant authentication failures. I fear that the dovecot-passdb file is wonky. Can anyone give me any pointers ?