Odds are if your page loads correctly in Netscape or some other browsers, and not in IE or Opera, it might be something rendered differently in the HTML.

I haven't used 9iAS yet, but generally the request the browsers send should all be the same, it's what they do after they get the information that varies. Try loading the page in Netscape or a working browser and saving the HTML which is generated, and see if that loads in the other browsers, could just be some mismatched tags that the other browsers don't handle the same.

Of course this could be way off the mark as I'm not sure exactly what the problem is :)