I'm having this same problem. My form is halfway down this page - http://smartbridge.com/demand-webinar-mystery-mobile-bi-dashboards-will-rule-2015/
Before I made it live, it wasn't like that. But then I remembered I needed a hidden field so I went back and added that, and ever since the submit button is really far away. I tried adding the hidden field on the 3rd column, next to the last name so it wasn't on a new row, but that didn't help.
I'm using the widget embed code so I can redirect to a new page. Any ideas?