There is $_REQUEST super-global variable in PHP, that used to contain Get/Post/Cookie variables all together. However since PHP 5.3.0 actual contents of this variable can be altered using "request_order" ini setting.
Unfortunately by default it no longer contains Cookie values. This is not big issue for In-Portal because it uses it's own $_REQUEST-alike variable maintenance system.
However it's a problem for Debugger, which thinks that there are always all variables inside a $_REQUEST and some of them are Get, some Post and some Cookies.