What's the actual problem you are having?
I wouldn't change to $_REQUEST. $_REQUEST is a merging together of other superglobals, and instead you should be specifying which superglobal you are retrieving from. Unless you've configured the directive, it will include cookie as an override to any form input.
Also, if you've modified the php.ini, you must restart the apache services in order for the new directives to be set.
header('HTTP/1.1 420 Enhance Your Calm');