Configuration problem with AuthMySQL

I have a directory that I want to protect with AuthMySQL. The following is the directory directive I created:

<Directory "/var/www/html/cufs/cufsauth/">
    AuthName "CUFS Alumni"
    AuthType Basic
    AuthMySQLUser uuuuuuuu
    AuthMySQLPassword pppppppppp
    AuthMySQLEnable on
    AuthMySQLPwEncryption scrambled
    AuthMySQLDB cufsalumni
    AuthMySQLUserTable alumni
    AuthMySQLNameField username
    AuthMySQLPasswordField pwdp
    require valid-user
</Directory>

Code (markup):

The problem is that this works when I use a link pointing to just the directory (assuming access to index.html). However, if I explicitly enter a file name in the URL, the authentication dialog does not occur and access is granted. Can someone help me correct my configuration? TIA.