That can be caused by some PHP applications and the way PHP is set to parse. Do you know if you have the ExecCGI function enabled for your domains vhost?
It would be followed after the "Options" directive in your httpd.conf, .htaccess or wherever your virtual host record is maintained on the server.
If you cannot locate anything related to your Options for your virtual host you can create a directory record in your httpd.conf for the directory and enable it.
Allow from all