column header and copy template is missing when using dropdownlist

[uniconstructor]

copy template and table header (when using table view) is empty by default. Clicking "add item" link adds only remove link and nothing more.

I found a solution by forcing "visible" attribute for every form element:

public function formConfig()
{
    return array(
        'elements'=>array(

            'event'=>array(
                'type'=>'text',
                'maxlength'=>255,
                'visible' => true, // copy template is empty without it!
            ),

            'year'=>array(
                'type'=>'dropdownlist',
                'items'=>array(''=>'-',2009=>2009,2010=>2010,2011=>2011,),
                'visible' => true, // copy template is empty without it!
            ),
        ));
}