apache2+mod_auth_pam-1.1.1_1 - BBS

OS:FreeBSD 5.4-REALEASE

問題簡述：
為了要讓使用者可以用 UNIX 帳號登入 http 認證管制的區域
於是安裝apache2 + mod_auth_pam-1.1.1_1
但是輸入帳號密碼卻無法順利登入
出現以下錯誤訊息

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.

安裝及設定部份：
# /usr/port/www/mod_auth_pam2> make install
# /etc/pam.d> vi httpd
auth required pam_unix.so no_warn try_first_pass
account required pam_unix.so no_warn try_first_pass
# /usr/local/etc/apache2> vi httpd.conf
LoadModule auth_pam_module libexec/apache2/mod_auth_pam.so
LoadModule auth_sys_group_module libexec/apache2/mod_auth_sys_group.so

<Location /mrtg>
AuthPAM_Enabled on
AuthType Basic
AuthName "Restricted Zone"
require group wheel
</Location>

另外網路上的文件有提到『using /etc/shadow with mod_auth_pam』
http://pam.sourceforge.net/mod_auth_pam/shadow.html
我有更改/etc/passwd及master.passwd的權限、群組
但是也行不通

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請問遺漏了什麼設定呢
多謝指教 :)

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如果問題敘述不清楚
也麻煩大家跟我說一下 @@

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