Form bindAndSave method doesn't save files - forms

Question

Parsing an XML feed and save it this way:
$action = new CouponActionForm();
$values = array(
'name' => $offer->name,
'link' => $offer->url,
'description' => $offer->description,
'discount' => $offer->discount,
'price' => $offer->price
);
$files = $this->getImages($offer->picture);
if(!$action->bindAndSave($values, $files)){
echo $action->renderGlobalErrors();
die('BAD THING');
}
Here is the getImages method:
private function getImages($url){
$ret = array('error' => 0);
$tmp_dir = sys_get_temp_dir();
$tmp_file = tempnam($tmp_dir, 'kupon');
if(copy($url, $tmp_file)){
$ret['tmp_name'] = $tmp_file;
$ret['name'] = basename($url);
$ret['size'] = filesize($tmp_file);
$ret['type'] = 'image/jpeg';
return array('filename' => $ret);
}else{
die('HELP');
}
}
Why do I use form saving instead of object saving with ->fromArray method ? Well, I already made the form and all validation, so I don't want to implement the same thing twice (DRY), but as important, I actually don't know how to use validators in doctrine model.
So the problem is that the form doesn't save files in specific directory specified by the path property of sfValidatorFile validator, but it exists in tmp directory.