[sork] Blank pages for sork modules (vacation, forwards, accounts)

[Wim]

Hi,
I have installed the 4 sork modules as descirbded in de documentation. 
The passwd module is working fine but when I try to access the 3 other 
modules I only got a blank page. I can see them in the left bar under 
'Myaccount'. When I go to the admin section they are not listed their.I 
have configured them also in config/register.php.
Did I forgot something ??
Many thanks.