I have two pages that are almost identical. However on the second page the vertical scroll is not appearing. The problem seems to be the fixed positioning on the nav menu. However, the same CSS is applied to both pages, the second one is using some additional styles that are included at the bottom of the CSS.
Heres the first page that keeps the nav menu fixed and scrolls fine:
http://jsfiddle.net/cGRT8/3/
And then second that doesn’t scroll:
http://jsfiddle.net/CC5d7/3/
You’re not properly closing your nav-container so your whole document being fixed. Fixed fiddle.