OK, I did get it to work. Don't know what went wrong.
Now all entries are bound to the the Validated Entries. And that works for the text fields. However, it does not work for the drop down menus (state and country). When I make a choice for billingstate and billingcountry and no choice for shippingstate and shippingcountry, I am returned to the checkout page with the error message next to the shipping menu entries. The billing menus are reset to their initial state (no choice), but have no warning next to them. When I leave them like that and fill in the shipping menus, I get returned to checkout page, this time with a warning next to the billing menus and the shipping menus reset .... I hope this is not to complicated.
Do drop down menus need special treatment?
And a general question: Once server validation is in place, is there any reason to keep spry validation?