Index: guestbook.module
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/guestbook/guestbook.module,v
retrieving revision 1.1.10.14.2.13
diff -u -p -r1.1.10.14.2.13 guestbook.module
--- guestbook.module	10 Mar 2009 23:14:57 -0000	1.1.10.14.2.13
+++ guestbook.module	18 Apr 2009 02:20:10 -0000
@@ -329,7 +329,8 @@ function guestbook_page($uid = 0, $op = 
 
   // Set last visited time for own guestbook
   if ($uid > 0 && $user->uid == $uid) {
-    user_save($user, array('guestbook_visited' => time()));
+    $account = (object) $user;
+    user_save($account, array('guestbook_visited' => time()), NULL);
   }
 
   // Delete or comment an entry