Help with apache and ldap authentication

[Bliss, Aaron]

I'm running redhat 3 es, apache and all modules including mod_authz_ldap
are from system rpm's; I'm attempting to restrict access to a directory
and would like to use ldap authentication; below is the relevant section
of my httpd.conf file; I'm getting the box to enter my credentials when
going to the web page, but it seems to be failing; any ideas?  Thanks
very much. 

<directory /webroot/www/nessus_summary>
 AuthType Basic
 AuthName "Private Area"
# AuthUserFile /usr/local/sbin/htusers
 AuthzLDAPEngine on
 AuthzLDAPServer "al-lnx-s11.preferredcare.org"
 AuthzLDAPBindDN "ou=users,dc=preferredcare,dc=org"
 #AuthzLDAPMapBase "ou=users,dc=preferredcare,dc=org"
 AuthzLDAPAuthoritative on
 AuthzLDAPSetAuthorization on
 Require valid-user
</directory>

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