Accordions not working properly

I am having issues with the accordion tabs not working properly. I am fully up to date with theme version 2.7 (I am using a child theme). And I have WordPress 3.9.

The problem is that only a few accordion tabs can be opened, and eventually, they all stop working. At this point, they cannot be opened/closed (sometimes one individual one can be openend/closed, but not the rest) unless the page is refreshed.

You can try it here: http://www.seatosummitworkshops.com/shop/photography-workshops/new-zealand-photography-tour/

Just open several tabs until it stops working.

I am using Windows 7 and Chrome browser and I even tried with all plugins disabled.

Thanks!