Thanks. I will give it a go later this week and see how it works. Yes, it was just the expanding menus issue that was a problem. Oh, and the menu appearing without formatting (FOUC) when the page first loads, but I think setting ‘display’ in the css can cure that.
I’ve since found another way of doing it with foundation menus, but it is good to have the smartmenus solution too, as your solution allows the top-level menu items to link to content as well.