IE7 Problems

Hello! Great plugin, saving me from writing the jquery code.

Anyway, I tested this on IE7, included the js media queries for old browsers, even latest jquery, but it seems that is not working something.

Is working well on the other new browsers.

What can cause that?

Thank you and waiting for your answer!

http://ww.wp.xz.cn/extend/plugins/responsive-select-menu/