Pie Show archive.org snapshot sometimes does not properly redraw elements upon changes. This often happens when the change comes from somewhere further up the DOM.

Rails Long Term Support

Rails LTS provides security patches for old versions of Ruby on Rails (2.3, 3.2, 4.2 and 5.2)

• Prevents you from data breaches and liability risks
• Upgrade at your own pace
• Works with modern Rubies

Read more Show archive.org snapshot

Consider something like:

<ul>
  <li class="active"><div class="content">Active element</div></li>
  <li class="inactive"><div class="content">Inactive element</div></li>
</ul>

with CSS
li .content {
-webkit-box-shadow: #666 0px 2px 3px;
-moz-box-shadow: #666 0px 2px 3px;
box-shadow: #666 0px 2px 3px;
behavior: url(/PIE.htc);

  background: white;
}
li.active .content {
  background: red;
}

If you now use JavaScript to add the class .active to another li, the contained .content (whose background should have changed) is not redrawn. If you were to add the .active class to the .content div (and change your CSS accordingly), it would work.

As a workaround, you can either touch the .content div's CSS in any way (by adding a bogus class for example) or change your markup.