Rails & FancyBox-Rails Not Working, throwing has no method 'fancybox' error-Collection of common programming errors

Just created a new Rails app & have run into some problems with fancy-box rails and am getting this error:

Uncaught TypeError: Object [object Object] has no method 'fancybox' 

Here is the JS being loaded at the bottom of my page:

Here is my fancybox JS:

jQuery(function() {
  $("a.grouped_elements").fancybox();
});

I have used this in previous projects are not seen this error.

I am using Rails 3.1.13, fancybox-rails 0.2.1, JQuery 1.10.2 and have followed the instructions on https://github.com/hecticjeff/fancybox-rails

Does anyone know why this might be happening?