[Dovecot] Dovecot 1.2rc4 - launchd keeps trying to restart it, after Dovecot exits with exit code: 89

[James Brown]

I know I should update to the release version (will do on Monday), but  
I keep getting this in my logs (ie All Messages shown):

4/07/09 11:50:18 PM Dovecot[742] Fatal: Dovecot is already running  
with PID 624 (read from /usr/local/var/run/dovecot/master.pid)
4/07/09 11:50:18 PM com.apple.launchd[1] (Dovecot[742]) Exited with  
exit code: 89
4/07/09 11:50:18 PM com.apple.launchd[1] (Dovecot) Throttling respawn:  
Will start in 10 seconds
4/07/09 11:50:18 PM com.apple.launchd[1] (Dovecot) Throttling respawn:  
Will start in 10 seconds
4/07/09 11:50:28 PM Dovecot[743] Fatal: Dovecot is already running  
with PID 624 (read from /usr/local/var/run/dovecot/master.pid)
4/07/09 11:50:28 PM com.apple.launchd[1] (Dovecot[743]) Exited with  
exit code: 89
4/07/09 11:50:28 PM com.apple.launchd[1] (Dovecot[743]) Exited with  
exit code: 89
4/07/09 11:50:28 PM com.apple.launchd[1] (Dovecot) Throttling respawn:  
Will start in 10 seconds
4/07/09 11:50:38 PM Dovecot[745] Fatal: Dovecot is already running  
with PID 624 (read from /usr/local/var/run/dovecot/master.pid)
4/07/09 11:50:38 PM com.apple.launchd[1] (Dovecot[745]) Exited with  
exit code: 89
4/07/09 11:50:38 PM com.apple.launchd[1] (Dovecot[745]) Exited with  
exit code: 89

Anywhere in particular that I should look for hints as to what is  
causing Dovecot to exit?

System is a Mac Mini Core 2 Duo running 10.5.7 (Leopard).

Thanks,

James.

dovecot -n:

# 1.2.rc4: /usr/local/etc/dovecot.conf
Warning: fd limit 256 is lower than what Dovecot can use under full  
load (more than 768). Either grow the limit or change  
login_max_processes_count and max_mail_processes settings
# OS: Darwin 9.7.0 i386  hfs
protocols: imap pop3 imaps pop3s
ssl_cert_file: /etc/dovecot/dovecot.pem
ssl_key_file: /etc/dovecot/dovecot.pem
disable_plaintext_auth: no
login_dir: /usr/local/var/run/dovecot/login
login_executable(default): /usr/local/libexec/dovecot/imap-login
login_executable(imap): /usr/local/libexec/dovecot/imap-login
login_executable(pop3): /usr/local/libexec/dovecot/pop3-login
login_user: _dovecot
first_valid_uid: 102
last_valid_uid: 105
mail_uid: 27
mail_gid: 27
mail_location: maildir:/usr/local/virtual/%d/%u
mail_executable(default): /usr/local/libexec/dovecot/imap
mail_executable(imap): /usr/local/libexec/dovecot/imap
mail_executable(pop3): /usr/local/libexec/dovecot/pop3
mail_plugin_dir(default): /usr/local/lib/dovecot/imap
mail_plugin_dir(imap): /usr/local/lib/dovecot/imap
mail_plugin_dir(pop3): /usr/local/lib/dovecot/pop3
auth default:
   mechanisms: cram-md5 login plain
   user: nobody
   failure_delay: 4
   passdb:
     driver: sql
     args: /etc/dovecot/dovecot-sql.conf
   passdb:
     driver: sql
     args: /etc/dovecot/dovecot-sqlmd5.conf
   userdb:
     driver: sql
     args: /etc/dovecot/dovecot-sql.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: 384