Highlight Current Menu Item: Home Not Working

Hello,

I’m currently building a theme and am having a small problem with wp_nav_menu. Firstly, here is my template code:

<?php wp_nav_menu( array( 'container_class' => 'menu-header', 'theme_location' => 'primary' ) ); ?>

And here is my CSS that controls the currently active menu item/page/post:

#access ul li.current_page_item > a,
#access ul li.current-menu-ancestor > a,
#access ul li.current-menu-item > a,
#access ul li.current-menu-parent > a {
    color: #FFF;
    background: #F45300;
    border: 1px solid #C84502;
    -moz-border-radius: 7px;
    -webkit-border-radius: 7px;
    border-radius: 7px;
    -moz-box-shadow:inset 0 0 4px #C64503;
    -webkit-box-shadow:inset 0 0 4px #C64503;
    box-shadow:inset 0 0 4px #C64503;
}

Now this is working perfectky for every single page/post except for my homepage. Does anybody know why? I am using a static homepage by the way.

Thanks!