maincore.php Problem, HELP!

<?php
/*---------------------------------------------------+
| PHPFusion 6 Content Management System
+----------------------------------------------------+
| Copyright © 2002 - 2006 Nick Jones
| http://www.php-fusion.co.uk/
+----------------------------------------------------+
| Released under the terms & conditions of v2 of the
| GNU General Public License. For details refer to
| the included gpl.txt file or visit http://gnu.org
+----------------------------------------------------*/
if (eregi("maincore.php", $_SERVER['PHP_SELF'])) die();

// If register_globals is turned off, extract super globals (php 4.2.0+)
if (ini_get('register_globals') != 1) {
   if ((isset($_POST) == true) && (is_array($_POST) == true)) extract($_POST, EXTR_OVERWRITE);
   if ((isset($_GET) == true) && (is_array($_GET) == true)) extract($_GET, EXTR_OVERWRITE);
}

// Prevent any possible XSS attacks via $_GET.
foreach ($_GET as $check_url) {
   if ((eregi("<[^>]*script*\"?[^>]*>", $check_url)) || (eregi("<[^>]*object*\"?[^>]*>", $check_url)) ||
      (eregi("<[^>]*iframe*\"?[^>]*>", $check_url)) || (eregi("<[^>]*applet*\"?[^>]*>", $check_url)) ||
      (eregi("<[^>]*meta*\"?[^>]*>", $check_url)) || (eregi("<[^>]*style*\"?[^>]*>", $check_url)) ||
      (eregi("<[^>]*form*\"?[^>]*>", $check_url)) || (eregi("\([^>]*\"?[^)]*\)", $check_url)) ||
      (eregi("\"", $check_url))) {
   die ();
   }
}
unset($check_url);

// Start Output Buffering
ob_start([color=#ff0000]ob_gzhandler[/color]);