Hmm I can see that you are using a bit too much code there...
here is a more optimized version:
code:
<style type="text/css">
#about a{
background-image: url('images/about.jpg');
float: left;
width: 59px;
height: 100%;
border:none;
display: block;
cue-after:none;
}
#about a:hover {
background-image: url('images/abouthover.jpg');
}
</style>
<div id="about">
<a href="http://www.google.pt" ></a> <a href="http://www.google.pt" ></a></div>
As you can see now that "#about a" and "#about a:hover" is defined you don't need to put " class="about" " in the link element. I have bolded what I changed
Hopefully you may find this helpfull