Worker does not register new function when I unregistered all earlier

[Jackson88]

Hi, I have a small problem with libgearman version => 1.1.12
(for libgearman version => 1.1.8 - all working fine)
I try to "$worker->addFunction()" after "$worker->unregisterAll()" and new function does not registered.

$worker->addServer('localhost', '4730');
//add test function
$worker->addFunction('test', 'test_function');
//unregister all
$worker->unregisterAll();
//try to add function
$worker->addFunction('test', 'test_function'); //- as result function no added