--- webform/components/fieldset.inc.orig	2012-09-18 20:46:59.000000000 +0200
+++ webform/components/fieldset.inc	2012-09-18 20:47:02.000000000 +0200
@@ -63,6 +63,7 @@
     '#collapsible' => $component['extra']['collapsible'],
     '#collapsed' => $component['extra']['collapsed'],
     '#attributes' => array('class' => array('webform-component-fieldset'), 'id' => 'webform-component-' . $component['form_key']),
+    '#id' => 'webform-component-' . $component['form_key'],
     '#pre_render' => array('webform_fieldset_prerender', 'webform_element_title_display'),
     '#translatable' => array('title', 'description'),
   );