IE wont use lightbox - 'Drupal' is not defined

I'dont test my site in IE frequently, so i don't know when the problem beggins.
I use lightbox for login form, and for showing images / both are not functioning in IE 7 (FF, Opera, Chrome, Safari are ok).
I only manage to find that the contact form "bug" is related to:
line 1296 of lightbox2.module

/**
 * Get the contact form.
 */
function lightbox2_contact() {
  if (module_exists('contact') && variable_get('lightbox2_enable_contact', FALSE) && user_access('access site-wide contact form')) {
    $path = drupal_get_path('module', 'contact');
    include_once($path .'/contact.pages.inc');
    print drupal_get_form('contact_mail_page');
    // drupal_add_js() with 'inline' didn't seem to work, possibly because this is
    // AJAX loaded content.
    <b>print '<script type="text/javascript">Drupal.attachBehaviors();</script>';</b>
    exit;
  }
}

It's there any solution?