Index: modules/system/system.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.module,v
retrieving revision 1.1003
diff -u -p -r1.1003 system.module
--- modules/system/system.module	4 Jan 2011 00:56:23 -0000	1.1003
+++ modules/system/system.module	6 Jan 2011 01:24:26 -0000
@@ -2019,6 +2019,7 @@ function system_block_info() {
   $blocks['help'] = array(
     'info' => t('System help'),
     'weight' => '5',
+    'cache' => DRUPAL_NO_CACHE,
   );
   // System-defined menu blocks.
   foreach (menu_list_system_menus() as $menu_name => $title) {