I have to say their support is the best I have ever seen.
They generated a new php file that submits the form data to mailchimp and displays the return response in your web browser for troubleshooting purposes.
I am not sure what caused the initial problem but I had exhausted all my email address testing the mailchimp generated form and the Form Builder form and was deleting the contacts from the mailchimp list that were generated using the mailchimp form so I could use them again in the Form Builder form.
When Form Builder tries to submit a contact that has been deleted in mailchimp it throws the data in the bit bucket and does not generate any kind of an error. Something that they may change in the future but I am not sure.
I will retrace my steps back and see if I can break it again and determine what actually corrected the problem.
I would contribute this partly to user error and ambiguous documentation about a deleted contact in a mailchimp list.
I hope this helps someone in the future.
Mike
