8.03.409C Invalid Tax Code

We recently moved from 8.03.305 to 409C. Now when entering AR invoices that come from packing slips, the sales tax information sometimes comes in and sometimes doesn't. We used to be able to just click new sales tax and it would add a line. Now we figured out that we can go to Calculate Taxes under the Actions menu but if we need to change the default we cannot. We have a Minnesota customer that defaults in with MN sales tax but if the product is delivered to ND we need to be able to charge them ND tax. Any idea why these fields would be greyed out and not allow us to make changes?