twitter badge not working – upgrade issue?

I’ve recently upgraded to WP 2.7 and set up a local site for testing (also running 2.7, but 2.7 was the first install, not an upgrade).

After upgrading, I added the basic HTML twitter badge to my sidebar, and it’s working on my local site but not on my live site. Here’s my sidebar.php code:
(TWITTERNAMEHERE* is replaced in my code with my twitter name)

<div id="sidebar">

<?php if ( !function_exists('dynamic_sidebar')
        || !dynamic_sidebar() ) : ?>
 <!-- <h2>Monthly Archives</h2>
  <ul>
    <?php wp_get_archives('type=monthly'); ?>
  </ul> -->

<div id="twitter_div">
<h2 style="display: none;" >Twitter Updates</h2>
<ul id="twitter_update_list"></ul>

</div>
<script type="text/javascript" src="http://twitter.com/javascripts/blogger.js"></script>
<script type="text/javascript" src="http://twitter.com/statuses/user_timeline/TWITTERNAMEHERE*.json?callback=twitterCallback2&amp;count=1">
</script>

  <h2>CATEGORIES</h2>
  <ul>
    <?php wp_list_categories('title_li='); ?>
  </ul>

  <ul>
   <?php wp_list_bookmarks(); ?>
  </ul>
<!-- <h2>Stay Updated</h2>
  <ul id="feed">
    <li><a href="<?php bloginfo('rss2_url'); ?>" title="<?php _e('Syndicate this site using RSS'); ?>">RSS Articles</a></li>
  </ul> -->
<?php endif; ?>

<!-- <div id="searchdiv">
    <form id="searchform" method="get" action="./index.php">
      <input type="text" name="s" id="s" size="20"/>
      <input name="sbutt" type="submit" value="Find" alt="Submit"  />
    </form>
  </div>  -->

</div>