[Fedora-directory-users] group problem

hi i use now FDS as group database here is a group i defined dn: cn=toto,ou=Groups,dc=sorbonne,dc=fr cn: toto objectClass: top objectClass: groupOfUniqueNames objectClass: posixGroup objectClass: groupofnames gidNumber: 16000 memberUid: uid=bob,ou=People,dc=sorbonne,dc=fr id bob give me : uid=51117(bob) gid=16000 what did i forget to do this group a unix group thanks basile