Got the error shown in Summary when using the formCheckbox helper to render a checkbox. Tested against zendframework-zf2-release-2.0.0rc2-86-g8fb1930

// sample form
namespace Web\Form;
use Zend\Form\Form;
class Test extends Form
{
    public function __construct($name = null)
    {
        parent::__construct($name);

        $this->setAttribute('method', 'post');

        $this->add(array(
            'name' => 'testcheck',
            'attributes' => array(
                'type' => 'checkbox',
                'checked' => false,
            ),
            'options' => array(
                'label' => 'Test option',
            ),
        ));
    }
}

// sample controller
public testAction()
{
    $form = new \Web\Form\Test();
    return array('form' => $form);
}

// sample view script
<?php echo $this->formCheckbox($form->get('testcheck')); ?>