multiple post type registration

Hi to all
I try many different way to register multiple post type, one works, the second no and I can’t spot why!

My last test was about:
– require_once('portfolio-type.php'); on functions.php file

-in portfolio-type.php I put the double registration like that:

if ( function_exists( 'add_theme_support' ) ) {
    add_theme_support( 'post-thumbnails' );
    set_post_thumbnail_size( 280, 210, true ); // Normal post thumbnails
    add_image_size( 'screen-shot', 720, 540 ); // Full size screen
}

add_action('init', 'genera_post_type'); 

function genera_post_type(){

	portfolio_register();

}

function portfolio_register() {
    $args = array(
        'label' => __('Portfolio'),
        'singular_label' => __('Project'),
        'public' => true,
	'has_archive'=>true,
        'show_ui' => true,
        'capability_type' => 'post',
        'hierarchical' => false,
	'show_in_menu' => true,
	'show_in_nav_menus'   => true,
        'rewrite' => true,
        'supports' => array('title', 'editor', 'thumbnail')
       );  

 $args2 = array(
        'label' =>'Ideas',
        'singular_label' => 'Idea',
        'public' => true,
	'has_archive'=>true,
        'show_ui' => true,
        'capability_type' => 'post',
        'hierarchical' => false,
	'show_in_menu' => true,
	'show_in_nav_menus'   => true,
        'rewrite' => true,
        'supports' => array('title', 'editor', 'thumbnail')
       );  

    register_post_type( 'idea' , $args2 );
    register_post_type( 'portfolio' , $args );
}

For portfolio I got no problem, everything is correct.
For Idea post type everything works but when I try to visit a generated post I always see a 404 error of page not found.
I try to add single-idea.php or not, but same result in both case, I try to register the post in different context but same result…
How can I solve this?
Many thanks in advance