HTML5 Shiv not working in IE7

I'm sure this is probably something really simple but I can't see the woods for the trees. For some reason HTML5 Shiv isn't loading. In IE7 my HTML5 tags nav, header, footer don't perform as expected. What am I missing?

Preview: http://dyingtounderstand.thecreativecollective.com.au/

Much appreciated.

Solution

Well I just checked your site in IE7 and it is loading the shiv, its likely to be a CSS layout problem in IE7.

shiv loaded in ie7

As a sanity check try styling the header and footer elements with a background-color just to see if you can target those elements.

Then work out why IE7 is messing up your layout.