joomla 1.5 plugin ldap

[supalg]

hye,
I have install joomla beta_fr 1.5 on linux environnement. I have a openldap server.
Under the joomla admin menu, I fed the differents fields but in /var/log/openldap, I have the following error but I don't understand what is wrong.
"bind: invalid dn (gros)"    ( gros is the login used)
Here is what I have entered in the fields :

Auto Create Users : No
Hôte : xxx.xxx.xxx.xxx.xxx (openldap server IP number)
port: xxx
LDAP V3 : yes
Négocier TLS : no
Ne pas suivre les référents : no
Nom absolu (DN) : ou=people,dc=xxxx.xxxx.xxxx,dc=xxx
Fonction de connexion:
Mot de passe de connexion:
Requête de recherche : uid[login]
DN Utilisateurs (Noms absolus) : ou=people,dc=xxxx.xxxx.xxxx,dc=xxx




Note: I just have declare the user 'admin' in the user table.

thanks for your help !  :'(