Index: modules/system/system.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.install,v
retrieving revision 1.389
diff -u -p -r1.389 system.install
--- modules/system/system.install	20 Sep 2009 17:56:24 -0000	1.389
+++ modules/system/system.install	26 Sep 2009 04:12:13 -0000
@@ -332,6 +332,11 @@ function system_install() {
     drupal_set_installed_schema_version($module, $version);
   }
 
+  // Clear out module list and hook implementation statics before calling
+  // system_get_theme_data().
+  module_list(TRUE);
+  module_implements('', FALSE, TRUE);
+
   // Load system theme data appropriately.
   system_get_theme_data();