Among others things I'm in charge of a Debian GNU/Linux (Wheezy) DomU for the mail services of the company i work for. Yesterday one HDD that was used for this particular server has died. After installing Debian again, Dovecot decided to no longer listen on any ports (checked with netstat -l). Other services (like Postfix and MySQL) work without problems.

dovecot -n:

# 2.1.7: /etc/dovecot/dovecot.conf
# OS: Linux 3.2.0-3-amd64 x86_64 Debian wheezy/sid ext3
auth_mechanisms = plain login
disable_plaintext_auth = no
first_valid_uid = 150
last_valid_uid = 150
mail_gid = mail
mail_location = maildir:/var/vmail/%d/%n
mail_uid = vmail
namespace inbox {
  inbox = yes
  location = 
  prefix = 
}
pass db {
  args = /etc/dovecot/dovecot-sql.conf.ext
  driver = sql
}
plugin {
  sieve = ~/.dovecot.sieve
  sieve_dir = ~/sieve
}
service auth {
  unix_listener /var/spool/postfix/private/auth {
    group = postfix
    mode = 0660
    user = postfix
  }
  unix_listener auth-userdb {
    group = mail
    mode = 0666
    user = vmail
  }
}
service imap-login {
  inet_listener imaps {
    port = 993
    ssl = yes
  }
}
service pop3-login {
  inet_listener pop3s {
    port = 995
    ssl = yes
  }
}
ssl_cert = </etc/ssl/private/mail.crt
ssl_key = </etc/ssl/private/mail.key
userdb {
  args = /etc/dovecot/dovecot-sql.conf.ext
  driver = sql
}
protocol imap {
  mail_max_userip_connections = 25
}

UID 150 is vmail (I double checked file permissions). I didn't install Dovecot from source, but via apt from the official Debian US mirror. There are no messages concerning Dovecot in /var/log/syslog except for:

Oct 21 06:36:29 server dovecot: master: Dovecot v2.1.7 starting up (core dumps disabled)

Any ideas?