Tax does not show on confirmation screen and e-mail

Hi,

Store URL: http://jakzdrowozyc.pl/products-page/
WordPress version: 4.2.2
WP eCommerce version: 3.9.3
Gold Cart version: N/A
Theme: Ciola

I did this:
I installed the plugin, configured, created a product. The problem I have is that tax (which is defined as 23%) shows correctly on the checkout page, but on transaction-results page is show as 0,00 PLN. It also shows 0,00PLN in confirmation e-mail sent to the client.
Taxes are turned on in settings. Additional settings are like this (translating from Polish):
1. Product price: second option
2. Indiwidual product tax: first option
3. Tax logic: first and subfirst options

I expected WPeCommerce to do this:
Show the tax correctly on transaction-results page and confirmation e-mail.

Instead it did this:
Tax showing zero 🙁

Thanks a lot for any help 🙂

https://wordpress.org/plugins/wp-e-commerce/