"adress family not supported by protocol" with ldap user

[Matthieu TURPAULT <Matthieu.Turpault@comelis.fr>]

Hello,

   I use OpenLDAP-2.0.11 and I try to run slapd as ldap user.

   When I run it as root, I have no problem.

   But when slapd runs as ldap (command /usr/sbin/slapd -u ldap -g ldap), I
have the following mitstake:
        segmentation fault
  
   ----------------
   syslog file:
   Jun 11 16:43:22 roxane slapd[30332]: daemon: socket() failed errno=97
(Address family not supported by protocol)
   Jun 11 16:43:22 roxane slapd[30332]: daemon: bind(6) failed errno=13
(Permission denied)
   Jun 11 16:43:22 roxane slapd[30332]: daemon: bind(6) failed
   Jun 11 16:43:22 roxane slapd[30332]: slapd stopped.
   Jun 11 16:43:22 roxane slapd[30332]: connections_destroy: nothing to
destroy. 
   -----------
   my slapd.conf:
   loglevel        256

   include         /usr/share/openldap/cmlsschema/core.schema
   include         /usr/share/openldap/cmlsschema/cosine.schema
   (...)

   (ACL)

   (...)

   pidfile         /usr/local/var/slapd.pid
   argsfile        /usr/local/var/slapd.args
   
   (...)
    
   atabase        ldbm
   suffix          "o=foo"
   rootdn          "cn=Manager,o=myfirm"
   rootpw          {SSHA}aJAs+c6UMSgj7GDcMRe+VhWvG+vsJqUx
   sizelimit       50000

   directory       /home/Directory20/loreal
   index   uid,objectClass eq
   index   telephonenumber pres
   index   title,mail,gn,sn,cn pres,eq,sub

   -----

    Any clues ??

   Thanks in advance