=== modified file 'includes/bootstrap.inc'
--- includes/bootstrap.inc                                                     
+++ includes/bootstrap.inc
@@ -615,12 +615,13 @@ function drupal_is_denied($type, $mask) 
  *
  * @return Object - the user object.
  */
-function drupal_anonymous_user() {
+function drupal_anonymous_user($session = '') {
   $user = new stdClass();
   $user->uid = 0;
   $user->hostname = $_SERVER['REMOTE_ADDR'];
   $user->roles = array();
   $user->roles[DRUPAL_ANONYMOUS_RID] = 'anonymous user';
+  $user->session = $session;
   return $user;
 }
 
=== modified file 'includes/session.inc'
--- includes/session.inc                                                       
+++ includes/session.inc
@@ -41,7 +41,7 @@ function sess_read($key) {
   }
   // We didn't find the client's record (session has expired), or they are an anonymous user.
   else  {
-    $user = drupal_anonymous_user();
+    $user = drupal_anonymous_user($user->session);
   }   

   return $user->session;