Problem with korganizer deleting items

Hi, I played a bit around with korganizer and probably imported items from another file. I am now unable to delete certain items. I can delete items that I created a minute ago, but not the older ones. Korganizer complains: "you are not the organizer of this event. Editing it will bring your calendar out of sync with the organizers calendar." Is there anything one can do about this? I checked the file std.ics, but it is not obvious to me in what way new entries differ from older ones. Thanks and greetings Stefan -- Stefan Müller Universität Potsdam Tel: (+49) (+331) 977-2180 http://www.cl.uni-bremen.de/~stefan/ http://www.cl.uni-bremen.de/~stefan/Babel/Interaktiv/