I think I see the problem.
Because you are using mod rewrite and querystring variables to tell the server what page to load, the server considers every page the index page.
is the same as:
as far as the Currant page submit trigger goes.
You mention earlier that you tried using the Button submit Order pressed trigger but that did not work?
Can you try again, if it does not work, send me a new copy of the page and a URL where I can see the problem in the browser.