Index: includes/common.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/common.inc,v
retrieving revision 1.688
diff -u -r1.688 common.inc
--- includes/common.inc	20 Sep 2007 08:30:34 -0000	1.688
+++ includes/common.inc	27 Sep 2007 05:27:13 -0000
@@ -306,11 +306,13 @@
   // Before the redirect, allow modules to react to the end of the page request.
   module_invoke_all('exit', $url);
 
-  header('Location: '. $url, TRUE, $http_response_code);
-
-  // The "Location" header sends a REDIRECT status code to the http
-  // daemon. In some cases this can go wrong, so we make sure none
-  // of the code below the drupal_goto() call gets executed when we redirect.
+  // Here we register header() to be called after exit(). Because
+  // session_write_close() was registered before header() all session
+  // data will be written to the database before the header is sent to the
+  // browser.
+  register_shutdown_function('header', "Location: $url", TRUE, $http_response_code);
+  
+  // Make sure none of the code below the drupal_goto() call gets executed. 
   exit();
 }