It’s still using the ‘old’ WPEC format where the checkout page is split over two pages instead of the latest version which is all on one page.
As the demo is not on the latest versions it makes it tricky to find/resolve issues because I can’t compare apples with apples. As a result I have previously raised one or two topics with Blanco support which means extra work for you. I wouldn’t have needed to bother you if there was a demo site that was on the latest versions.
When will you be udating the demo to the latest versions?
Is there an updated demo site somewhere else that your theme users can access?