Index: user.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/user/user.module,v
retrieving revision 1.823
diff -u -p -r1.823 user.module
--- user.module	25 Jul 2007 17:35:47 -0000	1.823
+++ user.module	25 Jul 2007 18:52:15 -0000
@@ -580,7 +580,7 @@ function user_user($type, &$edit, &$acco
 
 function user_login_block() {
   $form = array(
-    '#action' => url($_GET['q'], array('query' => drupal_get_destination())),
+    '#action' => url(('destination='. $_GET['q'] == drupal_get_destination()) ? NULL : $_GET['q'], array('query' => drupal_get_destination())),
     '#id' => 'user-login-form',
     '#validate' => user_login_default_validators(),
     '#submit' => array('user_login_submit'),