Hello,
I use the optional registration mode. If a new user put something in the cart and wants to register in the OPC formular, he gets an error message: "Could not validate checkout variables" after clicking on the button "confirm order". To complete the order, he have to confirm again.
The second problem I can not reproduce myself because I made no changes in configuration. I had two orders with an incorrect tax calculation, for example:
product 1: 24,95 €
product 2: 10,95 €
sub-total: 30,17 €
incl. tax: 6,78 €
shipping: 5,50€
total: 42,45 €
The total is to much, because the shipping tax is calculated twice.
In most cases and if I make a test order, the calculation is correct:
product 1: 24,95 €
product 2: 10,95 €
sub-total: 35,90 €
incl. tax: 6,61 €
shipping: 5,50€
total: 41,40 €
Hope you have an idea.
Best regards
Pierre