[Plugin: Responsive Select Menu] Not working with a background overlay.

I love the responsive menu created, simple and easy to use. The problem I’m facing now is when viewing from mobile devices, the responsive menu don’t work when the menu appear with a background overlay when scroll to a certain height.

Below is the code for the responsive menu with background overlay. This menu will appear when scroll to a certain height.

<div class="fixed-bar animated">
  <div class="container">
    <div class="row">
      <div class="col-2"><a href="<?php bloginfo('siteurl');?>/" title="<?php bloginfo('name');?>">
        <div class="logo"></div>
        </a></div>
      <nav class="col-10 last">
        <?php wp_nav_menu( array( 'theme_location' => 'primary' ,'container_class' => 'nav' ) ); ?>
      </nav>
    </div>
  </div>
</div>

This is the original set of menu that work even on mobile devices.

<header class="bg-cover">
  <div class="wrapper">
    <div class="grids">
      <div class="grid-2"><a href="<?php bloginfo('siteurl');?>/" title="<?php bloginfo('name');?>">
        <div class="logo"></div>
        </a></div>
      <div class="grid-10">
        <?php wp_nav_menu( array( 'theme_location' => 'primary' ,'container_class' => 'nav' ) ); ?>
      </div>
    </div>
    <div class="grids intro">
      <div class="grid-8">

      </div>
    </div>
  </div>
</header>

http://wordpress.org/extend/plugins/responsive-select-menu/