El siguiente código, aparte de mostrar lo mal que programo :), contiene algunos errores graves; en realidad, esta porción de código intenta reproducir un error observado en otra aplicación :-P .

<?php
/* Timer start */
$mtime = explode(' ', microtime() );
$timestart = $mtime[1] + $mtime[0];

include_once dirname(__FILE__) . '/db.php';

header( 'Content-type: text/html; charset=utf-8' );

if ( empty($_GET['category']) || !is_numeric($_GET['category']) ) {
	header( 'Location: error.html' );
}

$posts = $db->get_results("	
	SELECT 	posts.id, posts.name, posts.content, 
		    users.name as author
	FROM	posts, users
	WHERE 	posts.userid = users.userid AND
			posts.category_id = {$_GET['category']} 
	LIMIT 	10" );

?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "DTD/xhtml1-transitional.dtd">
<html xml:lang="es">

<head>
	<title>Search results</title>
</head>

<body>

	<div id="content">
	<?php if ( $posts ) : ?>

	<h2><?php echo count($posts); ?> elementos encontrados.</h2>	
	
	<?php foreach ( $posts as $post ) : ?>
		
	<div class="post">			
		<h4 class="post-meta">
		<a href="ver.php?id=<?php echo $post->id; ?>"><?php echo $post->name; ?></a> |
		<?php echo $post->autor; ?>
		</h4>
			
		<div class="content">
		<?php echo $post->content; ?>
		</div>
			
	</div>
		
	<?php endforeach; ?>

	<?php else : ?>
	
	<p>No se encontró ningún post en la categoría seleccionada.</p>
	
	<?php endif; ?>	
	</div>
	
	<div id="footer">
	
	<?php
	
	/* Timer stop */	
	$mtime = explode(' ', microtime());
	$timeend = $mtime[1] + $mtime[0];
	$timetotal = $timeend - $timestart;
	$time = number_format($timetotal, $precision);
	
	echo <<<STATS
<!--
Referer: {$_SERVER['HTTP_REFERER']}
User IP: {$_SERVER['REMOTE_ADDR']} 
-->

Página generada en {$time} segundos
STATS;
	?>
	</div>
</body>

</html>