Checkout Marketpress on one page

Checkout is not working anymore in 3 steps after the latest update.
After the shopping cart -->checkout
Normal you get the first step (billing information) and then you hit the button "next step"
but now I go directly to the payment gateway instead of step 2.

Because everything is now on one page but you cannot see those "hidden" steps

The next problem is when I leave the payment gateway (Mollie) and I want to go back to the site the order is confirmed but marked as "not paid" Customers never can pay this order any more.