LDAP Authentication

Hi,

I have a ldap group, "pgsql-developers". I have an user (user1) member
of this group;

group
dn: cn=pgsql-developers,ou=Groups,o=Dep,dc=x,dc=x,dc=x
objectClass: groupOfUniqueNames
objectClass: top
cn: SVN Committers
uniqueMember: uid=user1,ou=Users,o=Dep,dc=x,dc=x,dc=x

user
dn: uid=user1,ou=Users,o=Dep,dc=x,dc=x,dc=x
objectClass: person
objectClass: top
objectClass: uidObject
cn:: Denem1
sn:: Deneme2
uid: user1
userPassword:: e01ENX10WnhudnhscVIxZ1pIa0wzWm5ET3VnPT0=

I added this line to pg_hba.conf [1]

host all all 172.20.0.0/16 ldap
"ldap://localhost/basedn;cn=;,cn=pgsql-developers,ou=Groups,o=Dep,dc=x,dc=x,dc=x"

But now postgresql requires my user1 must be define under
cn=pgsql-developers,ou=Groups.. But I want to give login permission to
pgsql-developers members.

How can I change this line for give login permission to
pgsql-developers members?

[1] http://wiki.postgresql.org/wiki/LDAP_Authentication_against_AD