twitter-bootstrap – Bootstrap：在Breadcrumb中下拉

我的标记(Bootstrap 2.1.0)：

<ul class="breadcrumb">
  <li class="dropdown open">
    <a class="dropdown-toggle" id="branches" role="button" data-toggle="dropdown" href="#">default <b class="caret"></b></a>
    <ul id="branches-dropdown" class="dropdown-menu">
        <li><a tabindex="-1" href="...8109a3a986c7">commissions - <code>8109a3a986c7</code></a></li>
        <li><a tabindex="-1" href="...76d3a7022f9e">dashboard-integration - <code>76d3a7022f9e</code></a></li>
        <li><a tabindex="-1" href="...4ee00eb42b72">default - <code>4ee00eb42b72</code></a></li>
        <li><a tabindex="-1" href="...10755b086192">led-support - <code>10755b086192</code></a></li>
        <li><a tabindex="-1" href="...298fa9e18508">stable - <code>298fa9e18508</code></a></li>
        <li><a tabindex="-1" href="...990826c5d5df">xdm-customer-SELEction - <code>990826c5d5df</code></a></li>
    </ul>
    <span class="divider">/</span>
  </li>
  <li>
    <a href="...4ee00eb42b72">aeroclub.aeroexpress</a> <span class="divider">/</span>
  </li>
</ul>

我在这里做错了吗？