PHP __construct bug

<?php

class MyClass {

    // The singleton
    private static $msSingleton = null;

    // A number to check the singleton.
    public $foo = 0;

    private function __construct()
    {
        echo "Construct the class\n";
    }

    public static function getSingleton()
    {
        if(is_null(self::$msSingleton)) {
            self::$msSingleton = new MyClass();
        }

        return self::$msSingleton;
    }

    public function __call($name, $arguments)
    {
        echo '__call called. $name = ' . $name . "\n";
        // Like the overriding of the new operator of C++.
        if($name == '__construct') {
            return self::getSingleton();
        }
    }

}

$a = MyClass::getSingleton();
$a->foo = 20;

$b = MyClass::getSingleton();
echo $b->foo . "\n";
$b->foo = 27;
echo $a->foo . "\n";

$c = $a->__construct();
$c->foo = 32;
echo $a->foo . "\n";

$d = new MyClass();
echo $d->foo . "\n";
$d->foo = 45;
echo $a->foo . "\n";