I just spent some time finding a bit of a glitch with WebMin and the Apache module. By default the PHP configuration portion of the httpd.conf file is configured to add index.php to the list of directory indices. If you try to override this setting in Webmin it never takes. You can add index.htm all day long but it simply won't add. A quick work around is to add index.htm to the various DirectoryIndex entries for the versions of PHP.