I'll preface this with the fact I do not understand sitemaps and while I have been trying to wrap my head around it for two days, I have way too much other stuff going on to figure them out beyond the basic concept. In order to really make my pitch to my boss to use Forrest I need to be able to use WordPerfect docs with it. WordPerfect does publish to XML, but using the DocBook DTD, not Simplified DocBook. I tried following the faq (http://forrest.apache.org/0.7/docs/faq.html#docbook) about using DocBook but I don't really get it all. I do have Norman Walsh's DocBook stylesheets and I put them into PROJECT_HOME\src\documentation\resources\stylesheets.

With this sitemap.xmap (just following the example in the faq):
<?xml version="1.0"?>
<map:sitemap xmlns:map="http://apache.org/cocoon/sitemap/1.0";>
<map:pipelines>
 <map:pipeline>
  <map:match pattern="**wp.html">
   <map:generate src="{project:content.xdocs}{1}wp.xml"/>
   <map:transform
     src="{project:resources.stylesheets}/docbook.xsl"/>
   <map:serialize type="xhtml"/>
  </map:match>
 </map:pipeline>
</map:pipelines>
</map:sitemap>

It fails at linkmap.html with a long bunch of treeprocessor stuff, and this BROKEN message: URI not found: Type 'xhtml' does not exist for 'map:serialize' at file: PROJECT_HOME/src/documentation/sitemap.xmap:9:34

Any help is appreciated.
Thanks
Addi