The store cart summary and store cart details server behaviors are supposed to be applied on the confirm.php page and not the confirm_cart.php page. Did you add those manually?
The confirm_cart page is submitted to several times during the checkout process to update shipping costs and allow the user to confirm the address and potentially update it.
I'd run the wizard again in another folder if you don't want to lose any changes you made and then use the same syntax from the wizard created pages to update yours.
Did this help? Tips are appreciated...
