Index: modules/user/user.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/user/user.module,v
retrieving revision 1.889
diff -u -p -r1.889 user.module
--- modules/user/user.module	22 Jan 2008 07:51:56 -0000	1.889
+++ modules/user/user.module	25 Jan 2008 20:02:03 -0000
@@ -148,6 +148,11 @@ function user_load($array = array()) {
     return FALSE;
   }
 
+  // Return the anonymous user object if not logged in.
+  if (isset($array['uid']) && $array['uid'] == 0) {
+    return drupal_anonymous_user();
+  }
+
   foreach ($array as $key => $value) {
     if ($key == 'uid' || $key == 'status') {
       $query[] = "$key = %d";