need help with apache21 + mod_auth_pam2

[cs]

Hi,

FreeBSD 5.3 REL
Apache21 2.1.4
mod_auth_pam2 1.1.1

httpd.conf:

LoadModule auth_pam_module libexec/apache21/mod_auth_pam.so
#LoadModule auth_sys_group_module libexec/apache21/mod_auth_sys_group.so

<VirtualHost *:443>
     DocumentRoot /var/www
     <Directory /var/www>
         Options FollowSymLinks
         Order deny,allow
         Allow from all
         DirectoryIndex index.html
         AuthType Basic
         AuthName "secure area"
         require user test
     </Directory>
     SSLEngine On
</VirtualHost>

apache error log:

[error] Internal error: pcfg_openfile() called with NULL filename
[error] [client x.x.x.x] (9)Bad file descriptor: Could not open password 
file: (null)


Any idea ?

Thanks.

-cs