Question

html5 new elements (header, nav, footer, ..) not working in IE

Answer 1

You need to include the HTML5 shiv script in order to allow styling of HTML5 elements in older IE browsers: http://code.google.com/p/html5shiv/

To use, include the following script in your element above your CSS:

<!--[if lt IE 9]>
<script src="//cdnjs.cloudflare.com/ajax/libs/html5shiv/3.7.3/html5shiv.min.js"></script>
<![endif]-->