AJAX加载外部内容导航div消失

Question

请参阅http://www.elitedeafpoker.com/dev/poker-players.html - AJAX加载内容很好，但为什么左侧导航在加载外部内容后会消失？我无法弄清楚这一点。

<article class="span3">
   <ul class="list-1">
       <li class="pokerplayers"><a href="#pokerplayers">EDPS Poker Players </a></li>
       <li class="playerofthemonth"><a href="#playerofthemonth">Players of the Month</a></li>
       <li class="playeroftheyear"><a href="#playeroftheyear">Players of the Year </a></li>
  </ul>
</article>
<article class="span9">
   <div id="content">
        Contents to load...
   </div>
</article>

Content.html（AJAX将此文件加载到id =“content”div）

<div id="pokerplayers" style="width:500px;">Poker Players</div>
<div id="playerofthemonth" style="width:500px;">Player of the Month</div>
<div id="playeroftheyear" style="width:500px;">Player of the Year</div>

谢谢！