title: Twitter-Bootstrap 2.1.0 affix plugin - doesn't work properly
body: <p>I try to use bootstrap affix (2.1.0) in one of my mvc4 project.
  It seems that .span3 and .span9 doesn't work properly if, after scrolling 50px, the .span9 content move to the left.</p>
  
  <p>I found this: <a href="https://stackoverflow.com/questions/12106168/text-moves-to-side-of-the-page-on-scroll-down">Text moves to side of the page on scroll down</a> but is not working. Adding floats to spans works somehow but is not "responsive". I think it must be a better solution.</p>
  
  <p>Does anybody make it work ?</p>
  
  <p>Here is my code (copy &amp; paste from bootstrap site). Where I did wrong ?</p>
  
  <pre><code>&lt;body data-spy="scroll" data-target=".bs-docs-sidebar"&gt;
  &lt;div class="container"&gt;
  ....
  &lt;div class="row"&gt;
    &lt;div class="span3 bs-docs-sidebar" data-spy="affix" data-offset-top="50"&gt;
      &lt;ul class="nav nav-list bs-docs-sidenav"&gt;
        &lt;li&gt;&lt;a href="#download-bootstrap"&gt;&lt;i class="icon-chevron-right"&gt;&lt;/i&gt; Download&lt;/a&gt;&lt;/li&gt;
        ....
        &lt;li&gt;&lt;a href="#what-next"&gt;&lt;i class="icon-chevron-right"&gt;&lt;/i&gt; What next?&lt;/a&gt;&lt;/li&gt;
      &lt;/ul&gt;
    &lt;/div&gt;
    &lt;div class="span9"&gt;
      ....
      &lt;section id="download-bootstrap"&gt;
  </code></pre>