Index: modules/user/user.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/user/user.module,v
retrieving revision 1.913
diff -u -r1.913 user.module
--- modules/user/user.module	2 Aug 2008 20:08:24 -0000	1.913
+++ modules/user/user.module	6 Aug 2008 21:39:55 -0000
@@ -1367,8 +1367,11 @@
 function user_external_login_register($name, $module) {
   global $user;
 
-  $user = user_load(array('name' => $name));
-  if (!isset($user->uid)) {
+  $existing_user = user_load(array('name' => $name));
+  if (isset($existing_user->uid)) {
+    $user = $existing_user;
+  }
+  else {
     // Register this new user.
     $userinfo = array(
       'name' => $name,