nested tabsets have ui-state-disabled copied from parent tabset

If I have a nested tabset and the parent tabset has a bad link (which gets disabled) the nested tabset has the link in the same position disabled. The following code shows this behaviour, the nested tabset in Tab 2 has its second tab disabled incorrectly.

<script type="text/javascript">

$(function() {

$('#tabset1').tabs();

$('#tabset2').tabs();

});

</script>

<div id="tabset1">

<ul>

<li><a href="#tab1"><span>Tab 1</span></a></li>

<li><a href="#"><span>FAIL</span></a></li>

<li><a href="#tab2"><span>Tab 2</span></a></li>

<li><a href="#tab3"><span>Tab 3</span></a></li>

<li><a href="#tab4"><span>Tab 4</span></a></li>

</ul>

<div id="tab1">

content tab1

</div>

<div id="tab2">

<div id="tabset2">

<ul>

<li><a href="#tab5"><span>Tab 5</span></a></li>

<li><a href="#tab6"><span>Tab 6 (incorrectly disabled)</span></a></li>

<li><a href="#tab7"><span>Tab 7</span></a></li>

<li><a href="#tab8"><span>Tab 8</span></a></li>

</ul>

<div id="tab5">

content tab5

</div>

<div id="tab6">

content tab6

</div>

<div id="tab7">

content tab7

</div>

<div id="tab8">

content tab8

</div>

</div>

</div>

<div id="tab3">

content tab3

</div>

<div id="tab4">

content tab4

</div>

</div>