DOCBOOK-APPS: dsssl1.77 html TOC linkage problem

[Doug du Boulay <ddb@R3401.msl.titech.ac.jp>]

The manual I am trying to adapt to docbook is split into 
two chapters, control lines/commands for several programs 
(one program per <sect1>) and descriptions of those programs, again
one program per <sect1> element.

I have tried to set up links between the sections of each chapter as follows
<chapter id="controls">
<Title>Program Controls </Title>
<sect1  id="ABSORB-cont">
<Title id="ABSORB-cont-long"><XRef LinkEnd="ABSORB-desc" 
endterm="ABSORB-desc-short">: Absorption corrections</Title>
<titleabbrev id="ABSORB-cont-short">ABSORB </titleabbrev>
<para>
</para>
</sect1>
</chapter>

<chapter id="descriptions">
<Title>Reference Manual</Title>
<sect1  id="ABSORB-desc">
<Title id="ABSORB-desc-long"><XRef LinkEnd="ABSORB-cont" 
endterm="ABSORB-cont-short">: Absorption corrections</Title>
<titleabbrev id="ABSORB-desc-short">ABSORB</titleabbrev>
<para></para>
</sect1>
</chapter>

Although this provides the desired functionality of switching back and forth 
between the control lists and the descriptive sections by selecting the title 
link/xref, sadly it breaks the TOC linkage, as well as the next/prev
links on each html page.

The resultant html for those items is rendered as  
<href><href>xreftext</href>titletext</href>
with only the innermost href active (tested with Mozilla and Konqueror). 
I am not sure if this is a dsssl (stylesheets 1.77)  bug, or just tag misuse 
on my part.

TIA for any pointers.
Doug