Index: drupal_web_test_case.php
===================================================================
--- drupal_web_test_case.php	(revision 6482)
+++ drupal_web_test_case.php	(working copy)
@@ -1368,12 +1368,9 @@
       $this->pass($message, t('E-mail'));
     }
 
-    // Delete temporary files directory.
-    simpletest_file_unmanaged_delete_recursive($this->originalFileDirectory . '/simpletest/' . substr($this->databasePrefix, 10));
+    // Remove all temporary database tables and directories.
+    simpletest_clean_environment();
 
-    // Remove all prefixed tables (all the tables in the schema).
-    simpletest_clean_database();
-
     // Get back to the original connection.
     $GLOBALS['db_prefix'] = $this->originalPrefix;
 
Index: simpletest.module
===================================================================
--- simpletest.module	(revision 6481)
+++ simpletest.module	(working copy)
@@ -389,8 +389,8 @@
  */
 function simpletest_clean_environment() {
   simpletest_clean_database();
-  simpletest_clean_temporary_directories();
   if (variable_get('simpletest_clear_results', TRUE)) {
+    simpletest_clean_temporary_directories();
     $count = simpletest_clean_results_table();
     drupal_set_message(format_plural($count, 'Removed 1 test result.', 'Removed @count test results.'));
   }