Help with multiple loops

I’m definately a php novice but would like to display a loop within a loop.

My main post page looks like this

<?php get_header(); ?>
<div id="wrapper" class="clearfix" >
<div id="gencol" ><?php if (have_posts()) : while (have_posts()) : the_post();?>
<h2 id="post-<?php the_ID(); ?>"><?php the_title();?></h2>
<?php
include 'wp-content/themes/laca/whichnewsletter.inc.php';
the_content('<p>Read the rest of this page &raquo;</p>'); ?>
<?php endwhile; endif;
include 'wp-content/themes/laca/viewothers.inc.php'; ?>
<?php edit_post_link('Edit this entry.', '<p>', '</p>'); ?>
</div>
<?php get_sidebar(); ?>
</div>
<?php get_footer(); ?>

And my whichnewsletter.inc.php looks like this

<?php
// Let's make that thing that says "This article appears in the xx newsletter"
// Fall 2003
if (in_category('12')){?>
<p id="whichnewsletter">This article appears in the <a href="?cat=12">Fall 2003 Newsletter</a></p>
<?php
}
// Spring 2004
if (in_category('13')){?>
<p id="whichnewsletter">This article appears in the <a href="?cat=13">Spring 2004 Newsletter</a></p>
<?php
}
// Fall 2004
if (in_category('14')){?>
<p id="whichnewsletter">This article appears in the <a href="?cat=14">Fall 2004 Newsletter</a></p>
<?php
}
// Spring 2005
if (in_category('15')){?>
<p id="whichnewsletter">This article appears in the <a href="?cat=15">Spring 2005 Newsletter</a></p>
<?php
}
// Fall 2005
if (in_category('16')){?>
<p id="whichnewsletter">This article appears in the <a href="?cat=16">Fall 2005 Newsletter</a></p>
<?php
}
// Spring 2006
if (in_category('17')){?>
<p id="whichnewsletter">This article appears in the <a href="?cat=17">Spring 2006 Newsletter</a><br />
<a href="javascript:toggleLayer('articles');">view all articles from this newsletter</a></p>
<?php
}
// Fall 2006
if (in_category('18')){?>
<p id="whichnewsletter">This article appears in the <a href="?cat=18">Fall 2006 Newsletter</a></p>
<?php
}

Basically, I want to show a list of all articles within the specified category on a single post page. I tried using this code in the whichnewsletter.inc.php file but it causes the wrong content to be pulled from the first loop.

<div id="articles">
<ul>
<?php
query_posts('category=17'); while(have_posts()) : the_post();
?>
<li><a href="<?php the_permalink(); ?>" rel="bookmark" title="Permalink to <?php the_title(); ?>"><?php the_title(); ?></a></li>
<?php endwhile; ?>
</ul>
</div>

I hope I’m being clear. Thanks in advance for your help.
Ryan