diff -Naur phase3.old/includes/User.php phase3/includes/User.php
--- phase3.old/includes/User.php	2006-05-19 23:41:21.000000000 +0200
+++ phase3/includes/User.php	2006-05-19 23:44:19.000000000 +0200
@@ -1370,7 +1370,7 @@
 			$dbw =& wfGetDB( DB_MASTER );
 			$success = $dbw->update( 'watchlist',
 				array( /* SET */
-					'wl_notificationtimestamp' => 0
+					'wl_notificationtimestamp' => NULL
 				), array( /* WHERE */
 					'wl_user' => $currentUser
 				), 'UserMailer::clearAll'