Index: modules/simpletest/drupal_web_test_case.php
===================================================================
RCS file: /cvs/drupal/drupal/modules/simpletest/drupal_web_test_case.php,v
retrieving revision 1.92
diff -u -p -r1.92 drupal_web_test_case.php
--- modules/simpletest/drupal_web_test_case.php	30 Mar 2009 05:35:35 -0000	1.92
+++ modules/simpletest/drupal_web_test_case.php	21 Apr 2009 19:37:09 -0000
@@ -812,6 +812,10 @@ class DrupalWebTestCase {
    */
   protected function setUp() {
     global $db_prefix, $user;
+    // Reload module list and implementations to ensure that tests use a fresh
+    // copy during module installation.
+    module_list(TRUE);
+    module_implements(MODULE_IMPLEMENTS_CLEAR_CACHE);
 
     // Store necessary current values before switching to prefixed database.
     $this->originalPrefix = $db_prefix;