<?php
// sess_write never gets called

function sess_open($save_path, $session_name) {
        echo "session_open called<br>";
        return true;
}

function sess_close() {
        echo "session close called<br>";
        return true;
}

function sess_read($key) {
        echo "session read called<br>";
        return true;
}

function sess_write($key, $val) {
        echo "session write called<br>";
        return true;
}

function sess_destroy($key) {
        echo "session destroy called<br>";
        return true;
}

function sess_gc($maxlifetime) {
        echo "session gc called<br>";
        return true;
}

session_set_save_handler(
        "sess_open",
        "sess_close",
        "sess_read",
        "sess_write",
        "sess_destroy",
        "sess_gc");

class session{
 Function Session() {
                global $sessionActual;

                session_start();
                session_register( sessionActual );
        }
 Function addHistory( ) { 
                global $sessionActual;

                if ( !isset( $sessionActual ) )
                        $sessionActual = 0;
                else
                        $sessionActual += 1;
         }
}

$my_session = new session();
$my_session->addHistory();
?>

configured with:
'./configure' '--with-mysql' '--with-apxs' '--enable-trans-sid'