I have created a form in Designer 8, with the forms returned as PDFs. My problem is that half seem to come back with none of the boxes checked! I have followed up with several people to make sure they are completing the form, but when it gets to me only the text and drop-down boxes are complete.
This is for debugging only but you could add a button on the form and do a xfa.host.exportData() on th eclick event of the button. This will allow you to create a data file that represents the data in the form. Validate that the checkbox fields have a value. If they do not check the binding properties of the checkbox and make sure that it is not set to none.