on the page you sent, there are behaviors for both payflow pro and paypal express checkout, both are set to trigger on any form post, they are likely conflicting with each other.
most likely you have run the checkout wizard multiple times without deleting the original pages first.
if you are going to run the checkout wizard again, you need to first delete the origianl pages that where created.
delete you checkout pages, then re run the wizard for pay flow pro