Mr. Neil,
I believe I have found the cause of your issue. I downloaded the CSS and I simply saved a copy of the main page. In your CSS you have a couple of lines that read this:
width:930px; !was 730
(at the #container ID)
and
width:735px; !was 535
(at the #main ID)
You are using exclamation points to comment out the change. However in CSS the comments are done using /* at the beginning of the comment and */ at the end of the comment. So your comments are causing the CSS to become confused. Further there is a css rule !important that states to REALLY do what I just said. So if you change those to this:
width:930px; /*was 730*/
(at the #container ID)
and
width:735px; /*was 535*/
(at the #main ID)
Your problem should go away.
I tested it with my downloaded copy of your page and your style sheet and it worked fine.
If you have any further questions you can reach me at my email
boscagarda-programming@yahoo.com