Hmm, if you code it right, and make it standards-compliant, you shouldn't really have troubles of this nature.
The problem is, generally, that too many of us work using IE, and it isn't standards-compliant. I'd be interested in knowing if your page works in Mozilla or Opera on Win32.
This is hitting pretty close to home, actually; I have a quiz script up on the web that is pretty useful for its niche. I'm getting ready to move it from a "feature" on a low traffic site to a site that is basically dedicated to the subject. Now, when I wrote it (long time ago it seems) I was developing on Win32 with IE; nowdays I use Mozilla and Opera on FreeBSD, so I can have a very "local" development server (I'm typing on it at the moment ;-)
Anyway, on non-IE browsers I am told, even when I submit the correct answer, that my answer was wrong! "Sorry, the correct answer is "foo"; you said "foo"! I am thinking that using GET in a non-standard way can work on IE, but not on real browsers... if/when I get time to track it down, maybe we can discuss it further....