io per l'autoload uso questa
codice:
define('CLASS_DIR', 'phpClassesFolder/');
function __autoload($name) {
	if($exists = !class_exists($name) && file_exists($class = CLASS_DIR.$name.'.class.php'))
		require $class;
	elseif(!$exists) {
		eval('class '.$name.' extends Exception {}');
		throw new $name('[__autoload] this file doesn\'t exists: '.$class);
	}
}
qui hai un esempio