On SlideIn plugin, Mailchimp button not working

Hi,

WPMUDev's SlideIn plugin is exactly what I need.

However with Mailchimp enabled on a SlidIn, the submit button isn't working for me.

What did I do wrong?

Please try it on this page, for example:
http://javalush.staging.wpengine.com/23-excruciatingly-cute-dogs-living-coffee-farms/

(scroll down about 75% of the page, it will appear on the right)