Fields added to Order not validated during Checkout

I've added fields to the Order settings and marked them as required and used Fieldgroup Panes to display them in a pane during the checkout process. What I'm seeing is that even though the input elements are marked as required on the form, I can still advance to the next step without supplying values for them.

Also, for the fields which are not simple text, supplying an invalid value (e.g., entering 'adsfasdf' for an Email field) does not raise validation errors either.

I suppose I could write custom validations to do this, but it doesn't seem like that should be necessary for core functionality. I'd appreciate any suggestions for solutions or explanation of the behavior.

Posted: Jan 12, 2012