Callouts and profile-docbook.xsl don't seem to play well together

Hi,

I am using:
<screen>
xxxxxxx <co id="id-co" linkends="co"/>
</screen>
<calloutlist>
<callout arearefs="co-id" id="co">
<para>xxxx</pra>
</callout>
</calloutlist>

I am using xsltproc with xsl sytlesheets 1.61.3.

My .xml file validates using xmllint with xml-dtd 4.2.

When I use html/docbook.xsl as my stylesheet everything works fine.

When I use html/profile-docbook.xsl as my stylesheet, I get:
Error: no ID for contraint linkend: co.

If other confirm this problem, I would gladly submit it to the bug list at sf.net

Thanks.