Taxes are lost when using Modify Header Wizard
Steps to reproduce:
1. Create a sale for any party
2. Add a line with a product that has an accouting category with customer taxes set.
3. Click the "Modify Header" button and the Modify Button of the opened wizard.
After the wizard is closed the taxes are removed from the product.
I will expect that the taxes are set as they come from the product data.
I've found it on 5.4 series but I imagine that trunk is also afected.