[horde] horde redirect problem after initial setup

[Merk Matthias]

Hi List,

I've set Horde up an on a Debian 2.4 vServer with lighttpd-1.4.8 and 
mysqld  Ver 4.1.11
I followed the horde INSTALL docs to set it up. After creating the 
database i set up the authentication in horde to authenticate against 
PAM and entered my database details.
I logged and and can't log back in - i get the following log entries
firefox says this:
The page isn't redirecting properly.
Firefox has detected that the server is redirecting the request for this 
address in a way that will never complete.

I allowed my domain to set cookies.

about 8 per second of these entries in the lighty access log:
"GET /horde/login.php HTTP/1.1" 302 37 "-"

IE gets completely caught in this "redirect loop"
The only thing i've changed in the horde config is the webroot in 
config/registry.php
Does anyone know how to fix this?

Thx in advance!

MaceM