[horde] Participant is automatically registered when syncing Kronolith with iPhone

[Regina Reusser]

Dear list
 
I am running the latest version of Kronolith on Horde 5.0.1 and on my iPhone
4s there is iOS 6.0.1.
When I add a new event without adding a participant, my E-Mail-address is
automatically registered both on Kronolith and the iPhones calendar at the
participants section of the event after the synchronization, and on the
iPhone there is a symbole beside the appointment (voiceover tells me that
the event has to be confirmed). This happens also when I add the event on
the iPhones calendar.
Wenn I add a participant, even if I just press the space key once in the
participation field, the event appears as usual, without any symbols, on my
iPhones calendar after sync.
Must I always add a participant, or is there a setting I have forgotten?
 
Thanks and a nice weekend!
 
Regina