[Plugin: Collapsing Archives] display on a page?

I’m using this plugin, which works well in a sidebar. But not when I attempted to add it to a page template using this code:

<?php
     if( function_exists('collapsArch') ) {
      collapsArch();
     } else {
      echo "<ul>\n";
      wp_get_archives();
      echo "</ul>\n";
     }
    ?>

It displays the archives, but they don’t have the collapsing function.

Any advice on how to make this work on a page would be great!