$('body').height() is not necessarily correct

[mlb5000]

When calculating the viewport bounds in scrolled, $('body').height() is used to calculate bodyHeight. However, with full document scrolling (at least in Chrome and Firefox) the body height can be much smaller than the document height.

Changing $('body').height to $(document).height worked for me.

[eviltrout]

I'd happily accept a PR to make this change, assuming it works well :)