make a test page with errors turned on to see what's wrong with the sessions
<?php
session_start();
//turn on errors
ini_set('display_errors', 1);
error_reporting(E_ALL);
$_SESSION['test'] = (!isset($_SESSION['test'])) ? 1 : ($_SESSION['test']+1);
if ($_SESSION['test'] == 1) header('Location:?');
else echo "If the following number: ({$_SESSION['test']}), is greater than 1, your sessions work fine.";
?>