The pdf for the Reference Guide is not generated at the moment.
I think it was disabled in the main target but when I do:
[referenceGuide]$ ant lang.docpdf -Dlang=en
[java] [ERROR] file:/home/bdaw/Workshop/JBoss/portal/docs/trunk/referenceGuide/build/en/pdf/docbook_fop.tmp:4323:147 A table row must be child of fo:table-body, fo:table-header or fo:table-footer, not fo:table
[java] Java Result: 2
HTML is generated correctly so it doesn't seem to be wrong nested tags problem.