Index: wp-includes/canonical.php
===================================================================
--- wp-includes/canonical.php	(revision 7932)
+++ wp-includes/canonical.php	(working copy)
@@ -179,7 +179,8 @@
 	if ( strtolower($original['host']) == strtolower($redirect['host']) )
 		$redirect['host'] = $original['host'];
 
-	if ( array($original['host'], $original['port'], $original['path'], $original['query']) !== array($redirect['host'], $redirect['port'], $redirect['path'], $redirect['query']) ) {
+	if ( array($original['host'], @$original['port'], $original['path'], @$original['query']) 
+		!== array($redirect['host'], @$redirect['port'], $redirect['path'], @$redirect['query']) ) {
 		$redirect_url = $redirect['scheme'] . '://' . $redirect['host'];
 		if ( isset($redirect['port']) )
 		 	$redirect_url .= ':' . $redirect['port'];