Index: calendar/export.php
===================================================================
RCS file: /cvsroot/moodle/moodle/calendar/export.php,v
retrieving revision 1.24
diff -u -r1.24 export.php
--- calendar/export.php	31 Mar 2010 07:41:37 -0000	1.24
+++ calendar/export.php	3 May 2010 06:51:05 -0000
@@ -75,7 +75,7 @@
     $url->param('cal_y', $cal_y);
 }
 if ($course !== 0) {
-    $url->param('course', $course);
+    $url->param('course', $course->id);
 }
 $PAGE->set_url($url);