Mobile/default switch - cache issue

I'm working on a plugin to present a different layout to mobile users. It's partly working, you can have a look here: http://www.perjensen-online.dk/showroom/versatile/ login, pass: versatile

But it only works when Simple cache is turned of. When turned on, it only loads some of the changes.

My question is, how is the proper elgg way to switch between mobile and default view.