jquery - jquery error cannot call method '' of null

Question

I'm trying to implement this method: http://www.webtutorialplus.com/sticky-header-on-scroll-jquery/

with a sticky header on my website http://storkbox.gopagoda.com/

I want the grey menu to be sticky, but I get the error:

Uncaught TypeError: Cannot call method 'waypoint' of null 

at the line

$('.container').waypoint('sticky');

there is a div with a class of container on the page, so it should never be null

I don't know why, my only guess is that it's a difference between jquery 1.8.2 and 1.8.3, but can I run both instances at once (sticky plugin requires 1.8.3, and the rest of the plugins require 1.8.2)