Checkout taxes problem

[crackeclypse]

Hello, I have configured a store in PS 1.7, upon arrival at the checkout, the product in the cart appears with its total price (including taxes), within the checkout I enter step 1 of the customer data, and the Price well, however, when completing the address data, and adding the cost of the carrier, it takes away the taxes of the product, and as a total to pay it shows me a value without taxes + shipping cost. Someone could tell me what happened, I have not made major changes to the core, previously I did not have the problem. Thank you.