Index: includes/form.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/form.inc,v
retrieving revision 1.298
diff -u -p -r1.298 form.inc
--- includes/form.inc	27 Oct 2008 10:34:09 -0000	1.298
+++ includes/form.inc	28 Oct 2008 19:45:13 -0000
@@ -1994,7 +1994,15 @@ function form_process_checkboxes($elemen
     }
     foreach ($element['#options'] as $key => $choice) {
       if (!isset($element[$key])) {
-        $element[$key] = array('#type' => 'checkbox', '#processed' => TRUE, '#title' => $choice, '#return_value' => $key, '#default_value' => isset($value[$key]), '#attributes' => $element['#attributes']);
+        $element[$key] = array(
+          '#type' => 'checkbox',
+          '#processed' => TRUE,
+          '#title' => $choice,
+          '#return_value' => $key,
+          '#default_value' => isset($value[$key]),
+          '#attributes' => $element['#attributes'],
+          '#ahah' => isset($element['#ahah']) ? $element['#ahah'] : NULL,
+        );
       }
     }
   }