We have experienced an issue where a user is setup on the iSync Connector and the CalDAV setting for iCal. After the upgrade to 10.5.4, users are reporting that when they move a calender into a different order, iCal will rename all the calendars shared with the user to a number that represents its order in the list. It does not affect calendars that are located in the user's account. We have confirmed you can re-order calendars in iCal on 10.5.3 without this happening. Just FYI!
Bug filed:
29708
Version info:
iCal Version: 3.0.4 (1263)
iSync Connector Version: 5.0.2201
OS Version: OS X Leopard 10.5.4
ZCS Server Version: 5.0.4 GA (CentOS)