problem using get_posts inside a function. same code works properly outisde

Hello,
I’m experiencing a problem with the following snippet :
It works properly as a script (case 1) but when I put the exact same code into a function body, it always prints the same id (case 2) !

Case 1 code :

<?php
require('./wp-blog-header.php');

function br()
{
	echo '<br />'.'--------------------------------------------'.'<br />' ;
}

//return an associative array of all wp int post : master_translation_id => master_translated_modification_date

	$args = array(
    'numberposts'     => 1000,
    'offset'          => 0,
    'orderby'         => 'post_date',
    'order'           => 'DESC',
    'post_type'       => 'post',
    'post_status'     => 'publish' ); 

	$list_master_id_date =array() ;
	$lastposts = get_posts( $args );
	foreach($lastposts as $post)
	{
		setup_postdata($post);
		the_title();
		br();
		//the_content();
		the_id() ;
		br();
		//var_dump($post) ;
		$id=the_id();
		$post_custom_fields= get_post_custom($id) ;
		var_dump($post_custom_fields);
		br();
		//echo 'master_translation_id : '.$post_custom_fields["master_translation_id"][0].'<br>';
		//echo 'master_translated_modification_date'.$post_custom_fields["master_translated_modification_date"][0].'<br>';

		$list_master_id_date[$post_custom_fields["master_translation_id"][0]]=$post_custom_fields["master_translated_modification_date"][0] ;
	}
	//var_dump($list_master_id_date);

	//return $list_master_id_date ;

?>

Case 2 code:

<?php
require('./wp-blog-header.php');

function br()
{
	echo '<br />'.'--------------------------------------------'.'<br />' ;
}

//return an associative array of all wp int post : master_translation_id => master_translated_modification_date
function test()
{
	$args = array(
    'numberposts'     => 1000,
    'offset'          => 0,
    'orderby'         => 'post_date',
    'order'           => 'DESC',
    'post_type'       => 'post',
    'post_status'     => 'publish' ); 

	$list_master_id_date =array() ;
	$lastposts = get_posts( $args );
	foreach($lastposts as $post)
	{
		setup_postdata($post);
		the_title();
		br();
		//the_content();
		the_id() ;
		br();
		//var_dump($post) ;
		$id=the_id();
		$post_custom_fields= get_post_custom($id) ;
		var_dump($post_custom_fields);
		br();
		//echo 'master_translation_id : '.$post_custom_fields["master_translation_id"][0].'<br>';
		//echo 'master_translated_modification_date'.$post_custom_fields["master_translated_modification_date"][0].'<br>';

		$list_master_id_date[$post_custom_fields["master_translation_id"][0]]=$post_custom_fields["master_translated_modification_date"][0] ;
	}
	//var_dump($list_master_id_date);

	//return $list_master_id_date ;
}

test() ;
?>

Case 1 output :

international translation 2
--------------------------------------------
465
--------------------------------------------
465array(2) { ["master_translation_id"]=> array(1) { [0]=> string(4) "5119" } ["master_translated_modification_date"]=> array(1) { [0]=> string(19) "2012-08-09 09:12:11" } }
--------------------------------------------
international translation
--------------------------------------------
464
--------------------------------------------
464array(2) { ["master_translation_id"]=> array(1)

Case 2 output :

international translation 2
--------------------------------------------
465
--------------------------------------------
465array(2) { ["master_translation_id"]=> array(1) { [0]=> string(4) "5119" } ["master_translated_modification_date"]=> array(1) { [0]=> string(19) "2012-08-09 09:12:11" } }
--------------------------------------------
international translation 2
--------------------------------------------
465
--------------------------------------------
465array(2) { ["master_translation_id"]=> array(1) { [0]=> string(4) "5119" } ["master_translated_modification_date"]=> array(1) { [0]=> string(19) "2012-08-09 09:12:11" } }
--------------------------------------------

In my WP back office, I can see the two published posts with the IDs : 464,465.
Does anybody can help me ?
Thanks.
Greetings,
ben