css-fixed-layout-31-fixed-fixed-fixed?

[lostdog]

Using the css-fixed-layout-31-fixed-fixed-fixed on this site how can I get the background color or my left and right colums to extend to the footer? They currently only extend as far as the content in the colums. I have tried height: 100%;

[simcomedia]

http://matthewjamestaylor.com/blog/equal-height-columns-cross-browser-css-no-hacks