Can't make translated menus show up

As my primary links are rendered by the theme itself (Antsin-Blogbuzz) and I don't use a block to do so, I've tried to use « first method » by changing:

<?php if ($primary_links): ?>
 <div id="primary">
   <?php print menu_tree($menu_name = 'primary-links'); ?>
 </div>
<?php endif; ?>

into:

<?php if ($primary_links): ?>
 <div id="primary">
   <?php print $primary-links; ?>
 </div>
<?php endif; ?>

By this means not only I continue with the menu not showing up in languages other than the first one, but I get a menu populated by just a "0" in the main language.
Cold you, please, help me on this one ?