Anyone know why the animation is rough (doesn't really animate) on this bit of jquery?

$('.close').click(function() {
    $('.hidden-content').fadeOut('fast', function (){
        $('.serv-button').fadeIn('fast');
    });
});

Basically when you click on the close button a ".hidden-content" should fade out and the "serv-button"'s should fade in. But instead they just appear and do no fade. Here is my working example, it's on the services section:

http://www.hdesignonline.com/qdup/

Basically I need the content to fade out exactly how it fades in...