title: margin: 0 auto not working in IE only
body: <p>I am trying to center a div <code>#logo_alt</code> containing an image using <code>margin: 40px auto 0px auto;</code>.</p>
  
  <p><strong>Problem:</strong>: On Chrome, it looks perfect, but in IE, this img-containing div is aligned to the left of its parent container <code>#header_organizer</code>. I just cant figure out why this is happening, and how it can be fixed in IE! Any help greatly appreciated :)</p>
  
  <p><strong>HTML</strong></p>
  
  <pre><code>&lt;div id="header_organizer"&gt;
      &lt;div id="user_bar"&gt;...&lt;/div&gt;
      &lt;div id="user_bar_menu"&gt;...&lt;/div&gt;
      &lt;div id="logo_alt"&gt;                &lt;!-- &lt;&lt;&lt;&lt;&lt; We are centering this div! --&gt;
         &lt;img src="logo.png" \&gt;
      &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p><strong>CSS</strong></p>
  
  <pre><code>#header_organizer {
      width: 100%;
      height: 180px;
      background: black url(../images/template/header.png);
      float: left;
      position: relative;
      z-index: 1000;
  }
  
  #logo_alt {
      width: 256px;
      height: 55px;
      margin: 40px auto 0px auto;
  }
  
  
  #user_bar {
      height: 30px;
      color: #CCC;
      font-size: 13px;
      margin-right: 10px;
      padding: 0px 5px;
      float: right;
      cursor: pointer;
      position: relative;
      z-index: 3000;
  }
  
  #user_bar_menu {
      width: 200px;
      height: 165px;
      background: white;
      border: 1px solid #BEBEBE;
      float: right;
      position: absolute;
      top: 30px;
      right: 10px;
      -moz-box-shadow: -1px 1px 1px rgba(0,0,0,.2);
      -webkit-box-shadow: 0 2px 4px rgba(0,0,0,.2);
      box-shadow: 0 2px 4px rgba(0,0,0,.2);
      display: none;
      z-index: 1000;
      border-image: initial;
  }
  </code></pre>