Index.php 500 error

I recently decided to use punbb for my forum, and downloaded the 1.2.14 package. I uploaded all files and installed and uploaded the config.php file with no problems. However, when I try to go to index.php, the page loads for ages before giving a 500 Internal Server Error. Other pages show up fine, apart from search.php. I have searched the forums and gather that this is an issue alot of people have encountered, however I could not find any fixes which applied to me.

Site Link

Config.php is as follows

<?php

$db_type = 'mysql';
$db_host = 'localhost';
$db_name = 'xxxxxx';
$db_username = 'xxxxxx';
$db_password = 'xxxxxx';
$db_prefix = '';
$p_connect = false;

$cookie_name = 'punbb_cookie';
$cookie_domain = '';
$cookie_path = '/';
$cookie_secure = 0;
$cookie_seed = 'xxxxxx';

define('PUN', 1);

I would appreciate any help on this