youre causing the problem by setting a 100% height on the body tag in the css/basic.css file:
html, body, #outerWrapper, #contentWrapper {
height:100%;
min-height: 100%;
position:relative;
};
body > #outerWrapper {
position:relative;
height: 100%;
}
you want the outer wrapper and content wrapper to have 100% height, but not the body tag, this is what pushes the footer up the page.