Why do my forms have a clone of themselves in Firefox?

The 2 forms I added to our site look great on Chrome and Safari. But in Mozilla, they show a duplicate/clone of the form right below the original form and the screen keeps glitching. It is happening on both pages that I have forms on.

http://bataviafireworks.org/50-50/

http://bataviafireworks.org/city-wide-garage-sale/

I am assuming its a Mozilla thing. I read through your forum first and looked for duplicate embed codes and couldn't find anything in my coding. Any suggestions?

My website guy said this is what he found:

There is a glitch in their javascript that is causing it. They change the height of the iframe in which the form sits.

Actually, I finally found the duplicate embed code. Do you know why it works fine on all the other browsers? I didn't enter the code twice. All my text/code in Wordpress shows it posted only once.

Thank you for the update. I have just reviewed to verify your web pages and notice only one form page page. If you have copy and paste the code only once, it should only displayed once. 

Unfortunately, there is no reason of this. I will try to replicate the issue. If I am able I will let you know.