I'm receiving double submissions on my form

I am seeing consistent double submissions on my form.  They are about 2 seconds apart.  What would be causing this?  

I just noticed that when using the paypal information.  If they actually pay with paypal and not choose the option to pay by check it only submits once.

I think the submitters are experiencing a problem in the form such us the submit button is freezing up, they are getting stuck on "Please wait..." on submit making them to click the submit button twice.

Please try re-embedding the form using our iframe method: http://www.jotform.com/help/148-Getting-the-Form-iFrame-Code. If the above is indeed the reason, the iframe should fix it. Try it and let us know if the issue persists.

Thanks