When running the following script with register_globals off or on, i get proper results (the counter increments) under my production server (freebsd 4.5, php 4.1.2).  Under my devoplement box (Win 2k), I get nothing:

<?php

session_start();
  
if (!isset($_SESSION['count'])) {
    $_SESSION['count'] = 0;
} else {
    $_SESSION['count']++;
} 
  
echo $_SESSION['count'];
  
?>

Under win2k the session file is created in the proper directory, but is not populated with the registered variables.  The cookie is set on the client side.