Can't read $_POST array

I'm trying to write a VERY simple script that does nothing but store all the submitted GET and POST vars in a string and echo it out. $response = print_r($_REQUEST, true); echo $response; The problem is it only shows GET vars. I've tried $POST instead of $_REQUEST and it always gives an empty array. I've got it on two different servers, and we have three guys trying various methods of submitting forms to it, trying to eliminate all potential problems, like the possibility that the request might not actually have any POST vars. I think we've safely eliminated these possibilities. Can anyone see a reason why the above should not see POST vars? Is there some security setting I don't know about?