WAI-ARIA Bug

With the following HTML5 code, I get an error on the "tablist" role
assignment to <ul>. However, according to the HTML5 spec at
http://www.whatwg.org/specs/web-apps/current-work/multipage/elements.html#wai-aria
it says that it is a valid role for a <ul>.

Context:
<nav>
	<section role="tabpanel">
		<ul role="tablist" id="nav-tabs">
			<li role="tab"><a href="./?p=home" accesskey="1" title="Home">HOME</a></li>
			<li role="tab"><a href="./?p=gallery" accesskey="2"
title="Gallery">GALLERY</a></li>
			<li role="tab"><a href="./?p=user-list" accesskey="3" title="User
List">USER LIST</a></li>
			<li role="tab"><a href="./?p=events" accesskey="4"
title="Events">EVENTS</a></li>
			<li role="tab"><a href="./?p=videos" accesskey="5"
title="Videos">VIDEOS</a></li>
		</ul>
	</section>
	<hr>
	<section role="tabpanel">
		<ul role="tablist" id="doc-tabs">
			<li role="tab"><a href="./?p=home&amp;a=today" title="Latest
News">LATEST NEWS</a></li>
			<li role="tab"><a href="./?p=home&amp;a=dir" title="News
Archive">NEWS ARCHIVE</a></li>
		</ul>
	</section>
</nav>