Guestbook don't show IP

I've done it, but IP is still not shown

Ok which version of the guestbook are you using? If it is 2.3.4 it may be worth redownloading the full package again and replacing the add.class.php file in the lib folder and trying a preview entry again.

I have 2.3.1 version. So??

Download 2.3.4 and replace all your existing files except admin/config.inc.php

I've changed all tempates files source code. so when will I leave these files in unchanged form and i will replace all others files AGB will work properly??

I believe that a new item was added to form.php in version 2.3.3 so you will have to add that.