I needed to add a custom menu to the top of a website page for mobile only (there is a menu at the bottom for desktops and tablets). I created a custom menu in my Twenty Twelve child theme (called primary-mobile), added the code in the functions.php to register the menu, and then added the nav code to the header. All looks good ... except the menu button doesn't function. It was functioning in the bottom menu (in mobile). There is only one plug-in and it's not causing the problem. Is there something I'm missing, or does something need to be added to the navigation.js file?
Here are some links: