Affiliate Script

Hello,

I have an affiliate script integrated with my vbulletin and phpportals. The problem I'm having is that the affiliate script has a start_session call at the top of the page and that seems to be causing a problem. When I go to the url the page only loads 25% of the way but if I click refresh, the entire page loads.

Here's the sample page:
http://66.216.32.249/affiliates/user/

Here's a sample page that behaves that way:

PHP Code:

<?php
session_start();
include ("/usr/local/plesk/apache/vhosts/httpdocs/mainfile.php"); 
$index = 1;
global $menu_id,$menu,$Pmenu,$activeusers;
$Pmenu="P_thememenu_homepage";
include("/usr/local/plesk/apache/vhosts/httpdocs/header.php");
//include "/usr/local/plesk/apache/vhosts/httpdocs/affiliates/affiliate.php";
echo "Affiliate is $ref";
echo "<br>";
include("/usr/local/plesk/apache/vhosts/httpdocs/footer.php");
?>

Any ideas on how I can get around my sessions problem?

Thanks in advance!