Why is the third level not showing in my superfish menu?

Question

I'm having a super fish menu wih three layers of menu points but my second layer links do not seem to be expanding even tho "Show as expanded" is checked for the individual menu points (2nd level) that is selected as "Parent item" for the 3rd level page.

Some links:
menu point with submenus: http://www.lslib.ca/content/skwlax-daycare
Third level page(hidden from the menu): http://www.lslib.ca/content/admin

How can I get the third level to display?

EDIT 1

I don't exaxctly know how Superfish binds into the configration either.
Maybe a link to the page would help: http://www.lslib.ca/
Under Blocks, I only see Content assigned to a Region. I'm officially confused here... :o

EDIT 2

The name of the theme is Nexus Theme, under admin/appearance it says: Nexus Theme is a premium Drupal 7 theme. Developed by Devsaran.com.

In page.tpl.php I have the following:

<nav id="navigation" role="navigation">
  <div id="main-menu">
    <?php 
      if (module_exists('i18n_menu')) {
        $main_menu_tree = i18n_menu_translated_tree(variable_get('menu_main_links_source', 'main-menu'));
      } else {
        $main_menu_tree = menu_tree(variable_get('menu_main_links_source', 'main-menu'));
      }
      print drupal_render($main_menu_tree);
    ?>
  </div>
</nav>

Answer 1

I would give this a try:

In the drupal bloc configuration just disable "Slide-in effect"

Quoting the last comment from this thread: https://github.com/joeldbirch/superfish/issues/30

Hope you get lucky with this, that whole github thread could be also interesting/relevant to your issue.

Update: This is apparently a theme specific superfish implementation, the respective theme being (most probably) Nexus

In order to deactive the effects that could be causing the error, you should edit the file sites/all/themes/nexus/js/custom.js at about line 7, commenting out the animation options:

//  animation:   { opacity:'show',height:'show'},   // fade-in and slide-down animation 

Hope this does the trick!