Vars passed via URL disappearing

I just upgraded to PHP 4.2.2 and am trying to make my sites work with register_globals turned OFF. I notice, however, that with register_globals turned off any variables I pass via the URL don't seem to be recognized by the script it was passed to. So, if I pass "http://my.site.com/page.php?id=2002", the variable "id" is empty when I try to access it in page.php ... if (!empty($id)) { do stuff...} else { echo "error"; } With register_globals OFF, the above produces the error message. With register_globals ON, it works fine. I thought register_globals only affected session, cookie and get type variables? Why is PHP ignoring the variables passed via the URL? Thanks. Monty