Index: sites/all/modules/contrib/hierarchical_select/hierarchical_select.module
===================================================================
--- sites/all/modules/contrib/hierarchical_select/hierarchical_select.module    (revision 836)
+++ sites/all/modules/contrib/hierarchical_select/hierarchical_select.module    (working copy)
@@ -356,6 +356,12 @@
     }
   }

+  // if we have created form programattically we need call this
+  if( !function_exists("node_form")) {
+    module_load_include('inc', 'node', 'node.pages');
+  }
+
   // Retrieve and process the form.
   $form = call_user_func_array('drupal_retrieve_form', $storage['parameters']);
   drupal_prepare_form($form_id, $form, $form_state);