Inconsistencies in our SGML output

Does anyone know why the very same cross-reference,
     <xref linkend="reference">
renders as "Part VI" here:
    http://developer.postgresql.org/docs/postgres/sql.html
and on the next page as "Part VI in PostgreSQL 7.4beta1 Documentation":
    http://developer.postgresql.org/docs/postgres/sql-syntax.html
Given that we're building just one book now, the latter form seems
overly verbose to me.

Another oddity can be seen in the table of contents for the plpgsql
chapter,
    http://developer.postgresql.org/docs/postgres/plpgsql.html
Why is there no TOC entry for subsection 40.2.1?  It seems to be made
with <sect2> just the same as the other subsections.

            regards, tom lane