glossseealso in DocBook 5.0

Hello,

I tried today to add some "see also" statement in glossary entry,  
with DocBook 5.0 (latest snapshot).

I've done something like that :

<glossentry xml:id="SVN_Gloss">
	<glossterm>SVN</glossterm>
	<glossdef>
         	<para>
                    Blah blah blah
                 </para>
         </glossdef>
	<glossseealso><xref linkend="Subversion_Gloss"/></glossseealso>
</glossentry>

I made the same as or a <glosssee>.
But nothing appears in my PDF. I must do something wrong.

Thanks in advance for you help,
Jacques
-- 
« Mac OS X Server à votre Service » en vente au Monde en Tique.
<http://www.lmet.fr/fiche.cgi?_ISBN=9782952726603>
Attention, il ne reste que 17 exemplaires.