The following code:
$("#main-menu").smartmenus("itemActivate",$("#main-menu").find("a.current").eq(-1));
must be executed ondomready. So you need to change it like this:
$(function() { $("#main-menu").smartmenus("itemActivate",$("#main-menu").find("a.current").eq(-1)); });
However, unlike @YellowPhoenix, you are using a dropdown menu and not a collapsible one and it doesn’t make big sense to expand it on page load. You can see what I mean, when you fix the above.