[Dovecot] Auth Fails, But Can Still Get Mail

[Asai]

Greetings,

I've recently upgraded from version .97 to v. 1.2.  Everything seems to 
be working OK, but I'm wondering why I'm getting authentication failure 
messages in /var/log/maillog.  Like this:

Dec 15 11:02:41 triata dovecot: imap-login: Disconnected (auth failed, 1 
attempts): user=<mycenay>, method=PLAIN, rip=140.9.5.1, lip=140.9.5.1, 
secured


Although that user can log in to the server and get email no problem.  
Config file follows:

# 1.2.8: /etc/dovecot.conf
# OS: Linux 2.6.18-92.1.6.el5.centos.plusxen x86_64 CentOS release 5 
(Final) ext3
ssl_cert_file: 
/etc/ssl/triata.globalchangemultimedia.net/mailserver/smtpd.pem
ssl_key_file: 
/etc/ssl/triata.globalchangemultimedia.net/mailserver/smtpd.pem
login_dir: /var/run/dovecot/login
login_executable(default): /usr/libexec/dovecot/imap-login
login_executable(imap): /usr/libexec/dovecot/imap-login
login_executable(pop3): /usr/libexec/dovecot/pop3-login
mail_location: maildir:/vmail/%d/%n
mail_executable(default): /usr/libexec/dovecot/imap
mail_executable(imap): /usr/libexec/dovecot/imap
mail_executable(pop3): /usr/libexec/dovecot/pop3
mail_plugin_dir(default): /usr/lib64/dovecot/imap
mail_plugin_dir(imap): /usr/lib64/dovecot/imap
mail_plugin_dir(pop3): /usr/lib64/dovecot/pop3
namespace:
  type: private
  separator: /
  inbox: yes
  list: yes
  subscriptions: yes
namespace:
  type: public
  separator: /
  prefix: public/
  location: maildir:/vmail/public
  list: yes
lda:
  postmaster_address: postmaster at globalchangemultimedia.net
  hostname: triata.globalchangemultimedia.net
  mail_plugins: sieved
  mail_plugin_dir: /usr/lib64/dovecot/lda
auth default:
  mechanisms: plain login
  passdb:
    driver: pam
  passdb:
    driver: sql
    args: /etc/dovecot-mysql.conf
  userdb:
    driver: passwd
  userdb:
    driver: sql
    args: /etc/dovecot-mysql.conf
  socket:
    type: listen
    client:
      path: /var/spool/postfix/private/auth
      mode: 432
      user: postfix
      group: postfix
    master:
      path: /var/run/dovecot/auth-master
      mode: 432
      user: vmail
      group: vmail

-- 
--asai