I just uploaded it to a live test server to try it out, thinking that maybe it was a quirk with the xampp home server. I found out that it only did it on my local test site if I was logged in as a user, it was fine if not logged in. I went to your test site and registered and tried to checkout without anything in the cart and it displayed the time out page normally. So I thought, well it must be a funny xampp server issue. But, on my live test site hosted on a remote server it does the same thing. Go to
www.globalcustomdrums.com and log in as mattlong AT example DOT com password: password then click the checkout link in the header and tell me what happened. Maybe it's some weird quirk on my browsers? It does the same thing in IE7 and FF2.0.0.2.
Matt