WebSphere (probably others) not working with `itemtype="http://schema.org/Person"`

Following instructions at http://schema.org/docs/gs.html, I've marked up my HTML with:

<article class = "woman" itemscope itemtype = "http://schema.org/Person">
  <h3>
    <a href="http://en.wikipedia.org/wiki/Ada_Lovelace" itemprop = "url"><span itemprop = "givenName">Ada</span> <span itemprop = "familyName">Lovelace</span></a>
  </h3>

  <h4>(1815&ndash;1852)</h4>
  <img src="images/ada_lovelace.jpg" alt="Ada Lovelace" />
  <p>An analyst of Charles Babbage's analytical engine and is often
    described as the "<span itemprop = "jobTitle">first computer programmer</span>."</p>
</article>

WebSphere is complaining about the itemtype entry, if I try to fetch it, it says there is no XML at that point. Where should it be looking, and / or how am I supposed to wire this up? Schema.org is no fly-by-night new fangled thing, it's been around for ages. I'd have expected WebSphere to know all about it.