PHP Comparing Objects Bug

<?php

/**
 * Simple abstract class with one
 * protected property
 */
abstract class A
{
    /**
     * An errors array property
     * @var array
     */
    protected $errors = array();
}

/**
 * Simple class which extends A
 */
class B extends A
{
    /**
     * An errors array property
     * @var array
     */
    protected $errors = array();

    /**
     * Value from constructor
     * @var string
     */
    protected $value = null;

    /**
     * Method stores value in property
     *
     * @access  public
     * @param   string  $value  Value to store
     * @return  void
     */
    public function __construct($value)
    {
        $this->value = $value;
    }
}

// Creating new instance of B with "ABC" string
$object1 = new B('ABC');

// Creating new instance of B with "CBA" string
$object2 = new B('CBA');

// Both objects got different value of $value property
// They should be different, but PHP returns true here
var_dump($object1 == $object2);

// Printing first object
print_r($object1);

// Printing second object
print_r($object2);

// Comparing objects again but now PHP returns false
var_dump($object1 == $object2);