Help with Plugin for OpenX

[epic1]

I'm trying to get my old top banner rotation script working with my new vBulletin 4 installation.

This is my plugin code, hook location in global_start

PHP Code:

ob_start();

define('MAX_PATH', '/home/sites/fullthrottlev6.com/openx');
  if (@include_once(MAX_PATH . '/www/delivery/alocal.php')) {
    if (!isset($phpAds_context)) {
      $phpAds_context = array();
    }
    $topbanner = view_local('', 1, 0, 0, '_blank', '', '0', $phpAds_context, '');
ob_end_clean();

$preRegister['topbanner'] = $topbanner;
vB_Template::preRegister('header',$preRegister); 


In my header template, I have:

PHP Code:

{vb:raw topbanner} 


It's returning a blank spot. Any help? Thanks in advance!

--------------- Added [DATE]1279762707[/DATE] at [TIME]1279762707[/TIME] ---------------

Fixed.