I’m no CSS expert like the guys at Softpress but my trusty web developer’s tool in Firefox revealed a slight anomaly. At the bottom of the page there is a GIF spacer, which is set to float left, called _clear.gif, which is styled to be 1pixel deep. However it appears to have a width of -130, which might be causing the problem. The line of code is below:
Just spotted something else: did you intend to use Strict XHTML? The developer I work with had all sorts of problems recently with a site rendering incorrectly in IE (and other browsers, to be fair) and subsequently solved everything by re-publishing the page in Transitional XHTML.