Error when changing template in virtuemart

[zippo75]

Hi all!
I use Jommla by packing "VirtueMart_1.1.9_eCommerceBundle_Joomla_1.5.23.tar.gz" to build website. I create a template (name it template-1) to display news (it is the same "newspaper online"). It is working well. In this template, i create a menu "PRODUCTS". I create one more template (name it template-2) and i assign template-2 to menu PRODUCTS, because of i want when user click on PRODUCTS menu, it jump to template-2 (this template only for selling products) for buying products. Everything is ok. But after add to cart and check products is error appear.When update, delete products or change shipping address ...is it jump back homepage of template-1, so i can not do next step for checking out. Please help me to solve the problem.