I have found bug in File element. when I put file element into subform, then it doesn't have proper name.

Code snipet:

 
        $filesForm = new Zend_Form_SubForm();

        for ($h1=1;$h1<=5;$h1++) {
            $subForm = new Zend_Form_SubForm();
            $subForm->addElement('text', 'name', array(

            'filters'    => array('StringTrim' ),
            'validators'  => array('NotEmpty'),
            'label'      => 'Název ' ,
                    ));

            }

            $subForm->addElement('file', 'file', array(
            'filters'    => array('StringTrim', ),
            'label'      => 'Obrázek',
            'validators' => array (array('Size', false, 5*1024*1024),
                        array('Extension', false, 'jpg,png,gif'),
                        array('Count',false,1)),
                ));

            $filesForm->addSubForm($subForm,$h1);
        }

        $this->addSubForm($filesForm,'new_files');

...

then text elements have the proper names like : new_files[1][name] , so should file element, bu it is still named only file instead of new_files[1][file]

View script produces code like :

 Název Obrázek label of File Element is properly set, but its id and name doesn't contain parent arrays. I have found that 1.7.5 should have support for FileElement in subforms, but there is still this issue.