The theme is:
http://themeforest.net/item/limon-a-restaurant-and-spa-wordpress-theme/610441
I tried again switching to Twenty Eleven and after a lot of messing around with the menu i got it displaying the UberMenu and the FullCalendar plugin together. FullCalendar is one of the plugins that UberMenu has been interfering with. So it points to a problem with the theme and one or all of its built in plugins.
Although i am not sure how to solve it.