Validating a Custom Form with multiple validators in Symfony 2.5

I have an unbound form with two fields that i would like to validate. I would like to use the built in NotBlank on both fields and my two custom validators MyFile and *UploadConstraints *. The problem is i can get all three to work together. The UploadConstraints is called before the NotBlanks() and if i comment the UploadConstraints the attachment constraints does not fire, i used UploadConstraints to refer to both fields.

$builder
            ->add('country', 'entity',array(
                'class' => 'WarrDigicelBundle:Country',
                'property' => 'name',// display of countries
                'label' => 'Country:',
                'empty_value' => '',
                'empty_data'  => null,
                'required' => false,
                'constraints' => new NotBlank(),

            ))

            ->add('attachment', 'file',array(
                'label' => 'Upload:',
                'required' => false,
                'constraints' => new NotBlank(),
                'constraints' => array( new Constraints\MyFile())

            ))
            ->add('Upload File', 'submit')
        ;
    }

   public function setDefaultOptions(OptionsResolverInterface $resolver)
    {
        $resolver->setDefaults(array(
            'data_class' => null,
            'cascade_validation' => true,
            'constraints' => array( new Constraints\UploadConstraints())

        ));
    }