Issue with form

Hello-

We have a registration form we've been using for an upcoming event. Today we've received 2 registration confirmations that came back blank except for the contact info on the first page. Do you know why this would be happening? We have an email blast going out today and would like to get this figured out before that happens. 

I have just reviewed your form and did noticed that there were two submission with no information but the first page filled. Is it possible that the user did not filled in the rest of the information, since no other fields are required. The only required fields are in the first page.