lucy24 - 2:21 pm on Dec 23, 2012 (gmt 0)
Can't help but notice that you posted in the CSS forum, but didn't quote any of the relevant CSS. (Please! Not the entire style sheet! We don't care what font you use for the navigation links, or what your footer background image is called.)
One of the most common explanations is that one element is "hiding" another. Invisible, but still covering it in some way. Links have to be in the topmost layer.