Checkout Modification

I have a little problem, a thing that I don't like at all.
If a customer goes to checkout, after is editing the "Deliver To" it has to click AGAIN on the " Enter City and State and click here to update shipping rates"
If the customer changes something to Deliver To, the process for recalculating the taxes should be automatic. I have never seen this in my life. How is this possible?
I cant believe that cs-cart had made this mistake ...
Is there a way to make this process automatically?
We use the same rate for delivery for all products, all over the country