Atttribute id in <firstterm> prohibits link to glossary

When I do something like

A <firstterm id="def.Graph">graph</firsterm> is figure consisting of 
nodes and edges...

then the mechanism that creates HTML-links to a glossary entry "graph" 
does not work any more. No link is created. If I leave out the 
id-Attribut, everything works as expected.

Why is this so?

I am using the XSLT-stylesheets 1.61.0

I want to use the id-Attribute because sometimes I want to use this 
element a the target of a link - the place of the definition in my text, 
not in the glossary.

Greetings,
Joachim

-- 
Joachim Ziegler                       Stuhlsatzenhausweg 85
Max-Planck-Institut für Informatik    66123 Saarbrücken, Germany
Email:           Tel.: (+49) 0681 9325-127