Hello Barnez,
try changing
#footer ul (likely in your style.css file around line #252) to this...
#footer ul {
display: block;
margin:0 auto;
width: 660px;
}
the area basically is not centarable , if that's even a word, via text-align. sometimes it has to be done using a css style such as margin:0 auto; and assigning a smaller-than-100 percent width to the element. Personally not sure the exact reason, but usually text-align works well for paragraph contained elements, but not so much div ones. I'm sure there's a technical reason, but don't know it yet :) I did try the above edit using firebug css inspector and it worked fine. Let me know :)
Best Regards,
Danny