I was having similiar problems and it just depends on how your server is set up and if you have access to the .conf files.
First, try removing the <Files>..</Files> tag from your ForceType directive and see if makes any difference.
Change this...
<Files twmshn>
ForceType application/x-httpd-php
</Files>
to this...
ForceType application/x-httpd-php
This way ANY file without an extension is parsed as PHP
If that still doesn't work, try changing DefaultType in httpd.conf
From this:
DefaultType text/plain
To This:
DefaultType application/x-httpd-php
DefaultType is the default MIME type the server will use for a document if it cannot otherwise determine one, such as from filename extensions.
In Apache 2, there is a thing called AcceptPathInfo that needs to be set on for the directory that is using this method.
AcceptPathInfo On
See if that gets you any closer to your goal...
Cheers,
.dm