Strange issue that seems to only affect Leopard?
ZCS 4.5.6 with iSync Connector v4.5.1750 on Leopard 10.5.2
Syncing Zimbra Calendar with iCal works fine for additions. However, when removing (deleting) an appointment from the webUI, changes are not reflected after sync on iCal. The old deleted appointments remain in iCal which lead to fake double bookings.
I've attempted to reset the sync data from the local machine, which always did the trick on Tiger - However, the old deleted appointments remain in iCal. The only way I can seem to get rid of them is to manually remove them.