I'm having an issue with applying a coupon. When I click

I'm having an issue with applying a coupon. When I click "Apply coupon" on /signup, the page refreshes and goes back to the version of the /signup page that lists all the subscriptions.

You can test it here:
http://believedbehavior.com/wp/signup/

Choose SEASON 1 DIGITAL & PRINT U.S. $8. First you'll have to create an account and then try adding the coupon code FREEBIE8.

I'm running Version 3.4.4.2 of the plugin and Wordpress Version 3.6.1.