I've edited the wp-config.php (excerpt shown below), and created the DB, user, granted the user all permissions on the DB, and edited the keys. I've used mysql to login as the user with that password. Is there any other reason I'd get this error?
<?php
// ** MySQL settings ** //
define('DB_NAME', 'wordpress'); // The name of the database
define('DB_USER', 'wordpressuser'); // Your MySQL username
define('DB_PASSWORD', 'password'); // ...and password
define('DB_HOST', 'localhost'); // 99% chance you won't need to change this value
define('DB_CHARSET', 'utf8');
define('DB_COLLATE', '');
// Snip!
Cheers,
[sig moderated]