breaking long urls in pdf

I'm a new user of docbook and xep, working on formatting a medical book.

I tried the "inserting zero-width spaces after slashes" trick to make  
my long urls break nicely in a pdf.

Unfortunately, that caused xep to decide that, since the link text  
was now different from the link, it should display the link in square  
brackets following the link text. Like this:


*** XML

<para>For more information, see:
<ulink url="http://www.hopkinschildrens.org/specialties/categorypages/ 
intersex/">http://www.hopkinschildrens.org/&#x200b;specialties/ 
&#x200b;categorypages/&#x200b;intersex/</ulink></para>


*** PDF

For more information, see: http://www.hopkinschildrens.org/ 
specialties/categorypages/intersex/
[http://www.hopkinschildrens.org/specialties/categorypages/intersex/]

How can I suppress this behavior?

Thanks,

Cheryl