"Keep inclusive prices the same after a rate.." does not work

Hi Everybody,

i got uebercart up and running and it works fine so far. I added 2 taxes, 19% for one country, 20% for others.
Once i change the billing adress, it updates the taxes and the final price.

However, i want the final price always to be the same.

So lets say my product costs 120€. I checked sell price under "Select the price fields below that you will enter inclusive of VAT." and made the sell price 120€.

Deafult tax ist calculated with 19%, so it´s €100,84 + €19,16 = €120,00

I change the billing adress country, it now says: €100,84 +€20,17 = €121,01

It is my understanding that by using the "Keep VAT inclusive prices the same after a rate change." The final price should always be 120€ ?

I´m not sure it this is a bug / documentation/ settings issue..

Thx in advance, John