[finestshops]

Try this:

add in customer/home_main.tpl

{elseif $main eq "newest"}
{include file="customer/main/newest.tpl"}

in newest.php

at the beginning add

require "./auth.php"; 

and at the end:

$smarty->assign("main","newest"); 
$smarty->display("customer/home.tpl");

do not forget to remove

require "./newest.php"; 

from home.php

now try to run http://www.domain.com/store/newest.php
Should work if I did not miss something

Or just order this mod here:
http://www.shopping-carts-upgrades.com/Newest-Products-Added-p-91.html

and we'll set it up this way.