In times of ever increasing mobile web usage dropdown menus should be abandoned since they rely heavily on the hover state which doesn't exist on touch devices.
I ran some tests on this menu. It fails on android 2.3.x and 4.x. Also does it really need JS to function properly. No it doesn't, CSS already has all the features needed.
Further, a menu with a responsive design, such as the following, negates the need to abandon anything:
http://jasonweaver.name/lab/flexiblenavigation/