modulo de autentificacao na web (mod_auth_pam apache)

Bom Dia segue meu httpd.conf

httpd.conf
--------------------
LoadModule auth_pam_module modules/mod_auth_pam.so
LoadModule auth_sys_group_module modules/mod_auth_sys_group.so


e a autentificacao abaixo

<Directory /home/httpd/html>
AuthPAM_Enabled on
AuthAuthoritative off
AllowOverride None
AuthName "Family Secrets"
AuthType "basic"
require group users
</Directory>


/etc/pam.d/httpd
--------------------
#%PAM-1.0
auth required /lib/security/pam_unix.so
account required /lib/security/pam_unix.so

Volta está mensagem de erro

Authorization Required
This server could not verify that you are authorized to access the document requested. Either you supplied the wrong credentials (e.g., bad password), or your browser doesn't understand how to supply the credentials required.


/var/log/httpd/errors
--------------------------
[Thu Sep 08 10:03:49 2005] [error] [client 192.168.254.4] PAM: user 'teste' - not authenticated: Authentication failure


O Cliente está no grupo users, mas não autentifica!!!

Alguém pode me ajudar ?