Active Directory plus iCal = pain
This is sure being a pain
Lots of poorly documented stuff:
- http://support.apple.com/kb/HT3660 - Actually make calendar server work with Active Directory by disabling digest auth.
- http://support.apple.com/kb/HT3897 - Oh, by the way, iCal Server Utility doesn't actually do the delegation it advertises. You have to use the CLI.