Spry tabbed panels and "The tag: "li" doesn't have an attribute: "tabindex" ..."

Question

Hi,
I've been using the DW CS4 "Spry Tabbed Panels" on a few pages. When I validate the website (with DW tool for that), I get the following messages for each use of the tabbed panels: The tag: "li" doesn't have an attribute: "tabindex" in currently active versions. [XHTML 1.0 Transitional].
Should I worry about this? I'd like to have a code as clean and XHTML valid as possible. Is there a way to fix this so the message doesn't come up anymore?
Emilie
Example of code this message is linked to:
<div class="TabbedPanels" id="TabbedPanelsADMS">
  <ul id="TabUL" class="TabbedPanelsTabGroup">
    <li id="TabLI1" class="TabbedPanelsTab" tabindex="0">About</li>
    <li id="TabLI2" class="TabbedPanelsTab" tabindex="0">Assets</li>
    <li id="TabLI3" class="TabbedPanelsTab" tabindex="0">Input</li>
    <li id="TabLI4" class="TabbedPanelsTab" tabindex="0">Output</li>
    <li id="TabLI5" class="TabbedPanelsTab" tabindex="0">Support</li>
    <li id="TabLI6" class="TabbedPanelsTab" tabindex="0">Purchase</li>
  </ul>
  <div class="TabbedPanelsContentGroup">
    <!-- TabLI About -->
    <div class="TabbedPanelsContent">
      <!-- end #TabbedPanelsContent TabLI About -->
    </div>
    <!-- TabLI Assets -->
    <div class="TabbedPanelsContent">
      <!-- end #TabbedPanelsContent TabLI Assets -->
    </div>
    <!-- TabLI Input -->
    <div class="TabbedPanelsContent">
      <!-- end #TabbedPanelsContent TabLI Input -->
    </div>
    <!-- TabLI Output -->
    <div class="TabbedPanelsContent">
      <!-- end #TabbedPanelsContent TabLI Output -->
    </div>
    <!-- TabLI Support -->
    <div class="TabbedPanelsContent">
      <!-- end #TabbedPanelsContent TabLI Support -->
    </div>
    <!-- TabLI Purchase -->
    <div class="TabbedPanelsContent">
      <!-- end #TabbedPanelsContent TabLI Purchase -->
    </div>
    <!-- end #TabbedPanelsContentGroup -->
  </div>
  <!-- end #TabbedPanelsADMS -->
</div>

Answer 1

Should I worry about this? I'd like to have a code as clean and XHTML valid as possible. Is there a way to fix this so the message doesn't come up anymore?
If validation is important to you, you need to remove tabindex. Should you worry about it? Not really. Sometimes it makes sense to ignore validation to achieve a particular goal, which is why Spry widgets use tabindex in a technically invalid way.
The explanation as to why Spry does that can be found here: http://blogs.adobe.com/spryteam/2007/03/spry_widgets_and_tab_index.html.