Annoying error message since activated xmlrpc

Hi list !

Today I got the xmlrpc-connector for kontact and egroupware running :-)

Since then, every half minute or so I am getting a very annoying error 
message.
I have re-translated it from German (my kde-language) and I hope, somebody can 
read it anyway:

State of the ressource cannot be obtained

Error when getting folder information.
State of the folder cannot be obtained.

Trying to get the state of ressource Mail failed.
....

Technical cause: State of the ressource cannot be obtained.

Details:

* Adress: (unknown)
* Date and Time: ...
* Additional information: Mail

.......

I am sure, that this is not a mail-related problem, because all I changed was 
to setup xmlrpc for kontact.

Does anyone know how to get rid of this really annoying error-messages ?

Best regards and thanks in advance,

Otto