Question on internal communication of Kolab

Hi!

I played around a bit with the internal communication of Kolab.
AFAIK Kolab relays on XML-Objects stored in IMAP Folders.
So for each contact a Object in the Contacts-Folder of the IMAP-Server  
is created.
Now I tried to delete one of these via IMAP-Protocol (not by one of  
the Kolab-Clients)
But the contact is still viewable in Roundcube and can be edited.  
After editing the object is recreated in the contact-folder on the  
IMAP-Server.
Shouldn't the contact disappear in Roundcube?

So - where I'm going wrong in my considerations?

regards
Lukas