A cascata Doctrine2.3 e OneToOne persiste não parece funcionar

/**
 * User
 *
 * @ORM\Table("users")
 * @ORM\Entity
 */
class User extends UserEntity
{
    ...

    /**
     * @ORM\OneToOne
     * (
     *      targetEntity="UserPreferences",
     *      cascade={"persist", "remove"},
     *      inversedBy="user"
     * )
     */
    protected $userPreferences;
}

/**
 * @ORM\Table("user_preferences")
 * @ORM\Entity
 */
class UserPreferences extends UserPreferencesEntity
{
    /**
     * @ORM\Column(name="id", type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue
     */
    protected $id;

    /**
     * @var int
     *
     * @ORM\OneToOne(targetEntity="User", mappedBy="id", cascade={"persist", "remove"})
     */
    protected $user;

    ...
}

• http://docs.doctrine-project. org/en/latest/reference/unitofwork-associations.html
• http://docs.doctrine-project. org/en/latest/reference/association-mapping.html