Not validating file field

Hi,
Im dessesperated finding the solution of this issue.

i have this code in functions.php:

add_filter( 'wpcf7_validate_file', 'cf7_validate_file', 5, 3 );
add_filter( 'wpcf7_validate_file*', 'cf7_validate_file', 5, 3 );

function cf7_validate_file($result, $tag,$args)
{
	wp_die("exitting");
	if(is_array($args["uploaded_files"]))
	{ 
		return $result;
	}else
	{
	$result->invalidate( $tag,wpcf7_get_message( 'invalid_required' )  );
	$result['valid'] = false;
	return $result;
	}
}

But never load the funcion. If i change the filter for text it works, only happens with file validation.

Any help please?