PHP Autoloader Class

I am implementing an autoloader class and it's not working. Below is the autoloader class (inspired by this page on php.net):

class System
{
    public static $loader;

    public static function init()
    {
        if (self::$loader == NULL)
        {
            self::$loader = new self();
        }

        return self::$loader;
    }

    public function __construct()
    {
        spl_autoload_register(array($this, "autoload"));
    }

    public function autoload($_class)
    {
        set_include_path(__DIR__ . "/");
        spl_autoload_extensions(".class.php");
        spl_autoload($_class);
print get_include_path() . "<br>\n";
print spl_autoload_extensions() . "<br>\n";
print $_class . "<br>\n";
    }
}

The code that invokes the autoloader is here:

<?php
error_reporting(-1);
ini_set('display_errors', 'On');

require_once __DIR__ . "/system/System.class.php";

System::init();

$var = new MyClass(); // line 9

print_r($var);
?>

And the error messages:

/home/scott/www/system/
.class.php
MyClass
Fatal error: Class 'MyClass' not found in /home/scott/www/index.php on line 9

The autoload function is being hit, the file MyClass.class.php exists in the include path which I can verify by changing the code to this:

<?php
error_reporting(-1);
ini_set('display_errors', 'On');

require_once __DIR__ . "/system/System.class.php";
require_once __DIR__ . "/system/MyClass.class.php";

System::init();

$var = new MyClass();

print_r($var);
?>

print_r($var); returns the object and no errors.

Any advice or pointers?

As stated on the doc page for spl_autoload, the class name is lower cased before it looks for the class file.

So, solutions 1 is to lowercase my file, which is not really an acceptable answer for me. I have a class called MyClass, I want to put it in a file called MyClass.class.php not in myclass.class.php.

Solution 2 is to not use spl_autoload at all:

<?php
class System
{
    public static $loader;

    public static function init()
    {
        if (self::$loader == NULL)
        {
            self::$loader = new self();
        }

        return self::$loader;
    }

    public function __construct()
    {
        spl_autoload_register(array($this, "autoload"));
    }

    public function autoload($_class)
    {
        require_once __DIR__ . "/" . $_class . ".class.php";
    }
}
?>