[horde] installation problem with horde/imp: no remote access

[jeroen]

Dear all,

I already asked a couple of weeks ago, but I'm back at square one.
My horde/imp is not working remotely.
I first have some questions. I use mysql as a backend.
In the installation description there is nowhere a script to insert
users into the horde_users database. 
Should I insert them manually? I created one user, myself, but I still
can't IMP remotely. On my LAN it is working.
Does this mean that this kind of authentication is unrelated to
mailserver logins/passwords?
my /horde/test.php results in:
Warning: Unknown(/var/www/html/horde/test.php): failed to open stream:
Permission denied in Unknown on line 0
Warning: (null)(): Failed opening '/var/www/html/horde/test.php' for
inclusion (include_path='.:/usr/share/pear') in Unknown on line 0

But my /horde/imp/test.php seems to work just fine.

I created a tmp dir one dir above apache documentroot. Session data is
written into this dir, but the redirect fails. The server complains
"Cannot find server or DNS Error". When i move the tmp dir into the
documentroot range (also in the horde.cfg), the dir stays empty. 

Thanks for your help,
Jeroen.