This seems to help too.

diff --git a/login/logout.php b/login/logout.php
index 09e9fddb2e6edaa800ecdee17301a1f67f0a0b4c..298aaa9d28fe27bdf2a6997bbd78d8e5c617ae11 100644 (file)
--- a/login/logout.php
+++ b/login/logout.php
@@ -12,6 +12,9 @@
     unset($_SESSION['USER']);
     unset($_SESSION['SESSION']);
 
+    unset($SESSION);
+    unset($USER);
+
     redirect($CFG->wwwroot);
 
 ?>