[horde] how should vhosts option in configuration work?

[dev at stean.ch]

hello all,

i enabled $conf[vhosts] and made a copy of horde/config/registry.php
to horde/config/registry-www.example.com.php

all i changed in that file was the name of the horde application,
so instead of Horde to Example.

now that virtual domain its horde installation is broken, all i
get in the logs is:

Cannot redeclare _detect_webroot() (previously declared in  
horde/config/registry.php:501) in  
horde/config/registry-www.example.com.php on line 527

what am i doing wrong ?

thanks, and regards, stephan