Index: cck/content_crud.inc
===================================================================
RCS file: /cvs/drupal/contributions/modules/cck/content_crud.inc,v
retrieving revision 1.56
diff -u -r1.56 content_crud.inc
--- cck/content_crud.inc	1 Jan 2008 21:50:33 -0000	1.56
+++ cck/content_crud.inc	8 Jan 2008 03:18:03 -0000
@@ -326,6 +326,10 @@
 
   content_clear_type_cache(TRUE);
 
+  if ($prev_field['widget']['label'] != $field['widget']['label']) {
+    content_menu_needs_rebuild(TRUE);
+  }
+
   return $field;
 }