When adding posts, older posts disappear

I’ve got two templates set up for pages that I regularly update. They are “Writers in Schools,”(wins-blog.php) here: http://www.penfaulkner.org/writers-in-schools/wins-blog/

And “Podcasts,” (podcasts.php) here: http://www.penfaulkner.org/reading-series/podcasts/

The trouble is that after the first five posts display, the others go away and I can’t get to the previous posts using the “Previous Posts” and “Next Posts” links at the bottom of the page.

I’ve got a lot of content, and I want to make sure readers can access it. Any help would be appreciated! I’m a newb at this, clearly!

In my themes, the code at the bottom of the pages looks like this:

<div style=”clear:both”></div>

<?php endwhile; ?>
<div id=”next-previous”>
<?php next_post_link(‘%link’, ‘« Previous Posts’, TRUE, ”); ?> <!– last parameter is to exclude a category –>
           
<?php next_post_link(‘%link’, ‘Next Posts »’, TRUE, ”); ?> <!– last parameter is to exclude a category –>
</div>
</div><!–#excerpts–>
</div> <!–End entry-content –>
</div><!– #content –>
</div><!– #primary –>

<?php get_sidebar(); ?>
<?php get_footer(); ?>