[Excavator]

Yes, like I was kind of suggesting... the problem was far removed from what you were looking at.

In your CSS you have

.banner a {
    bottom: 30px;
    left: 20px;
    position: absolute;
}

Remove that and make your markup look something like this -

<article class="grid_4">
                    	<div class="banner">
                        <a href="#"><img src="images/banner-3.png" alt=""></a>
                    </div></article>