# Without validation it works (but doesn't validate of course):

$email = new Zend_Form_Element_Text('email');
        $email->setLabel('Email address')
              ->addFilter('StringToLower')
              ->setRequired(true)
              ->addValidator('NotEmpty');


# But if instead I try to validate, the webpage hangs indefinitely:

$email = new Zend_Form_Element_Text('email');
        $email->setLabel('Email address')
              ->addFilter('StringToLower')
              ->setRequired(true)
              ->addValidator('NotEmpty')
              ->addValidator('EmailAddress');