[Dovecot] dovecot: lda(foo): Error: User foo doesn't have home dir set, disabling duplicate database

[Christian Hoffmann]

Hello everyone,

I have a small problem with dovecot installed on ubuntu-13.10. I use 
dovcot as LDA with a LDAP-passdb and a pam-passdb. The userdb is static. 
A mail to LDAP-user 'foo' is delivered with the error-message

dovecot: lda(foo): Error: User foo doesn't have home dir set, disabling 
duplicate database

A mail to the pam-user 'bar' will deliverd without this error. But both 
users should work with the static-userdb. Where is my mistake?

Greetings
Christian

dovecot --version
2.1.7
############################################ my dovecot.conf
# 2.1.7: /etc/dovecot/dovecot.conf
# OS: Linux 3.11.0-22-generic i686 Ubuntu 13.10 ext4
disable_plaintext_auth = no
first_valid_uid = 107
last_valid_uid = 109
listen = *
log_timestamp = "%Y-%m-%d %H:%M:%S "
mail_home = /var/mail/%u
mail_location = maildir:/var/mail/%u/Maildir
managesieve_notify_capability = mailto
managesieve_sieve_capability = fileinto reject envelope encoded-character vacation subaddress comparator-i;ascii-numeric relational regex imap4flags copy include variables body enotify environment mailbox date ihave
passdb {
   args = /etc/dovecot/dovecot-ldap.conf
   driver = ldap
}
passdb {
   driver = pam
}
plugin {
   sieve = /var/mail/%u/dovecot.sieve
   sieve_before = /etc/dovecot/sieve.global/spamfilter.sieve
}
protocols = imap pop3 sieve
service auth {
   user = root
}
service managesieve-login {
   inet_listener sieve {
     port = 2000
   }
}
ssl_cert = </etc/exim4/exim.crt
ssl_key = </etc/exim4/exim.key
syslog_facility = local0
userdb {
   args = home=/var/mail/%u uid=Debian-exim gid=Debian-exim
   driver = static
}
protocol pop3 {
   pop3_uidl_format = %08Xu%08Xv
}
protocol lda {
   auth_socket_path = /var/run/dovecot/auth-master
   hostname = ods2.schule.de
   mail_plugins = sieve
   postmaster_address = postmaster
   sendmail_path = /usr/sbin/sendmail
}
############################## my dovecot-ldap.conf
uris = ldaps://my.ldap.host.edu
dn = chief
dnpass = secret
auth_bind = yes
ldap_version = 3
base = ou=Personen,DC=my,DC=ldap,DC=host,DC=eu
scope = subtree
pass_filter = (&(objectClass=user)(cn=%u)(memberOf:1.2.840.113556.1.4.1941:=cn=Mail,ou=Gruppen,DC=my,DC=ldap,DC=host,DC=eu))