isguest() must be checked AFTER require_login() because the user may not be logged in yet ;-)

mod/data/rate.php

@@ -1,11 +1,7 @@
-<?php
+<?php  // $Id$
     require_once("../../config.php");
     require_once("lib.php");
 
-    if (isguest()) {
-        error("Guests are not allowed to rate posts.", $_SERVER["HTTP_REFERER"]);
-    }
-
     $id = required_param('id',PARAM_INT);  // The course these ratings are part of
 
     if (! $course = get_record("course", "id", $id)) {
@@ -14,6 +10,10 @@
 
     require_login($course->id);
 
+    if (isguest()) {
+        error("Guests are not allowed to rate posts.", $_SERVER["HTTP_REFERER"]);
+    }
+
     $CFG->debug = 0;    /// Temporarily
 
     $returntoview = false;