Posts pagination in a page

Hello!

I’ve a custom theme and a page in it that display only posts from a specified category.

So, i’ve this code:

<?php
/*
Template Name: Pagina Eventi
*/
?>

<?php get_header(); ?>

<?php
$query= 'cat=4';
query_posts($query);
?>

<div id="content">
<table width="900px"  style="height:580px !important;" cellpadding="0" cellspacing="0">
[...]
<?php query_posts('showposts=4'); ?>
<?php if (have_posts()) : ?>

        <?php while (have_posts()) : the_post(); ?>
			[...]
            <div class="post">
                <h3 id="post-<?php the_ID(); ?>"><a>" rel="bookmark" title="Permanent Link to <?php the_title(); ?>"><?php the_title(); ?></a></h3>

                <div class="entry_eventi">
                    <?php the_content('Read the rest of this entry ?'); ?>
[...]

        <?php endwhile; ?>
</table>

<div class="navigation">
<div class="alignleft"><?php previous_posts_link('? Previous Entries') ?></div>
<div class="alignright"><?php next_posts_link('Next Entries ?','') ?></div>
</div>

    <?php else : ?>

        <h2 class="center">Not Found</h2>
        <p class="center"><?php _e("Sorry, but you are looking for something that isn't here."); ?></p>
        <?php include (TEMPLATEPATH . "/searchform.php"); ?>

    <?php endif; ?>
[..]
</table>

</div>
<?php get_footer(); ?>

Where “[…]” I’ve cut some html code.

Now, this code display correctly the “Next/Previous Entries”, but when I click on it the url become https://www.mysite.tld/page/2/ but posts remain the same than previous page, nothing change.

Where am i wrong?

Thanks

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