title: UIButton and selected highlight state
body: <p>The UIButton has a normal/default, highlighted, and selected image. I then have a <code>IBAction</code> method that is called on <code>Touch Down</code>. The method changes the highlighted image depending if it's selected. But when the button is selected, the method is called and so the highlight image is changed, however what is displayed is the normal/default image with a tint. I have tested that image used is in not <code>nil</code>. What happens is when the UIButton in a selected state is pressed displays the normal state with a tint. Why is it not using the highlight image and is there another way of showing a selected highlight image?</p>