Cannot get to the WP installer (wp-admin/install.php)

I’ve created a new folder on our server for a new WP install. I also used Plesk to create a new mySQL db. I put the db name, username and password into the config.php file, (just as I’ve done a squillion times before.) But when I go to the URL all I get is:

<?php
/* Short and sweet */
define(‘WP_USE_THEMES’, true);
require(‘./wp-blog-header.php’);
?>

I’ve tried downloading and installing a fresh copy of WP. I’ve tried creating another DB. I’ve tried everything I can think of, but no luck. This is the first time I’ve created the DB myslef–I wonder if I’m doing something wrong or if putting the WP install in a director other than the root has something to do with it.

Anyone?