La paginazione non funziona con il template dei risultati di ricerca

Non riesco a far funzionare correttamente la paginazione nel mio template dei risultati di ricerca. I link delle pagine appaiono, ma quando clicco sulla pagina 2, ricevo un errore 404.

Search.php

<?php
global $wp_query;
$total_results = $wp_query->found_posts;
?>

<?php
if(!$wp_query) global $wp_query;
$search_refer = $_GET["post_type"];
if ($search_refer == 'archive') { load_template(TEMPLATEPATH . '/search-gallery.php');}
else{load_template(TEMPLATEPATH . '/search-standard.php');}
?>

Codice di Paginazione in Functions.php

function pagination($pages = '', $range = 4){  
 $showitems = ($range * 2)+1;  

 global $paged;
 if(empty($paged)) $paged = 1;

 if($pages == '')
 {
     global $wp_query;
     $pages = $wp_query->max_num_pages;
     if(!$pages)
     {
         $pages = 1;
     }
 }   

 if(1 != $pages)
 {
     echo "<div class=\"pagination\"><span>Pagina ".$paged." di ".$pages."</span>";
     if($paged > 2 && $paged > $range+1 && $showitems < $pages) echo "<a href='".get_pagenum_link(1)."'>&laquo; Prima</a>";
     if($paged > 1 && $showitems < $pages) echo "<a href='".get_pagenum_link($paged - 1)."'>&lsaquo; Precedente</a>";

     for ($i=1; $i <= $pages; $i++)
     {
         if (1 != $pages &&( !($i >= $paged+$range+1 || $i <= $paged-$range-1) || $pages <= $showitems ))
         {
             echo ($paged == $i)? "<span class=\"current\">".$i."</span>":"<a href='".get_pagenum_link($i)."' class=\"inactive\">".$i."</a>";
         }
     }

     if ($paged < $pages && $showitems < $pages) echo "<a href=\"".get_pagenum_link($paged + 1)."\">Successiva &rsaquo;</a>";  
     if ($paged < $pages-1 &&  $paged+$range-1 < $pages && $showitems < $pages) echo "<a href='".get_pagenum_link($pages)."'>Ultima &raquo;</a>";
     echo "</div>\n";
 }
}

Template dei Risultati di Ricerca

<?php
    $paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
    $search_query = array(
        'posts_per_page' => '10',
        'paged' => $paged,
        );
    $wp_query = new WP_Query($search_query);

    if ($wp_query->have_posts()) : while ($wp_query->have_posts()) : $wp_query->the_post(); ?>


<div class="courseContent coursesLayout alumniMainContent alumniSpacing newsBoxMore">
        <div class="courseContentHolder alumniContentHolder newsBoxMainHolder">
            <div class="newsMainImage">
                <?php the_post_thumbnail(); ?>
            </div>

            <div class="alumniHeading newsMainHeading">
                <h5><?php the_title();?></h5>
            </div>

            <div class="alumniContent newsMainContent">
                <?php the_excerpt(); ?> 
            </div>
        </div>
        <span class="readmoreButton" style="display: inline !important;"><a title="Premi Studenteschi" href="<?php the_permalink();?>">Leggi tutto</a></span>
</div><?php edit_post_link('Modifica'); ?>
<?php endwhile; ?><?php else : ?>       
    <p class="notfoundtext">Spiacenti, nessun risultato trovato per la tua ricerca. Riprova?</p>
<?php endif; ?>     

<?php pagination(); ?>

Qualche suggerimento?