Repeated messages : op=0 do_bind: invalid dn (uid=,ou=...

[Frank Bonnet]

Hello

since few time I get those repeated messages in syslog
Jul  8 10:20:18 ldap slapd[28833]: conn=312612 op=0 do_bind: invalid dn 
(uid=,ou=Personnes,dc=xxxxx,dc=fr)


this happen exactly every minute

Anyone could give me some pointers ?

Thanks