I am actually struggling with the following setup. And I'm really glad if someone could help me or give me any hints.

We have some executives here wich are using the following setup:
Zimbra 5.0.9 <-> Leopbard 10.5.4/5 <-> Connector 5.0.3325 CalDAV <-> iPhone 1.1.x

iPhone/iTunes/iCal/Apple (please check what's applicable) does not allow to fully synchronise the iPhone Calendar to the Zimbra Server. On the iPhone, synchronised appointments from the Zimbra Server cannot be modified or deleted. On the other hand, newly created appointments on the iPhone cannot be synchronised to a CalDAV calendar. iTunes only allow local calendars to be used for new appointments.

Does someone have a similar setup or could give me any hints?

Thanks in advance!
- Dan