[Dovecot] could someone check my conf files for dovecot and postfix

[Trish]

*>  dovecot -n*
# 1.2.9: /etc/dovecot/dovecot.conf
# OS: Linux 2.6.32-31-generic i686 Ubuntu 10.04.2 LTS
log_timestamp: %Y-%m-%d %H:%M:%S
protocols: imap pop3 imaps pop3s
disable_plaintext_auth: no
login_dir: /var/run/dovecot/login
login_executable(default): /usr/lib/dovecot/imap-login
login_executable(imap): /usr/lib/dovecot/imap-login
login_executable(pop3): /usr/lib/dovecot/pop3-login
mail_privileged_group: mail
mail_location: maildir:~/Maildir
mbox_write_locks: fcntl dotlock
mail_executable(default): /usr/lib/dovecot/imap
mail_executable(imap): /usr/lib/dovecot/imap
mail_executable(pop3): /usr/lib/dovecot/pop3
mail_plugin_dir(default): /usr/lib/dovecot/modules/imap
mail_plugin_dir(imap): /usr/lib/dovecot/modules/imap
mail_plugin_dir(pop3): /usr/lib/dovecot/modules/pop3
auth default:
   passdb:
     driver: pam
   userdb:
     driver: passwd

I get this error in my log


May  6 20:33:00 craftboard dovecot: IMAP(support.perlygates.com): mail_location: maildir: Unknown setting: mbox
May  6 20:33:00 craftboard dovecot: IMAP(support.perlygates.com): Fatal: Namespace initialization failed

I'm not sure what mbox is.  But I am using the Maildir/ in conf file
Where is mbox set at?