I am still trying to debug this problem.
I have tried removing the Server account from Calendar Preferences as well as System Preferences, then readding. Did not work.
I tried doing the remove again, this time removing everything in Keychain associated with the Server Calendars. Did not work.
I tried going to ../<User>/Library/Calendars and navigating to the caldav directory associated with the server (this takes some poking around as the directory name is based on the server's hex identifier), then renaming the Info.plist file, then deleting the account from System Preferences, then recreating. Did not work. In fact the renamed Info.plist file was gone, but a new one was there.
The Info.plist file contained the bad entry in several places. This is what mine looks like (with specific servers and user names replaced):
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>AccountIsEnabled</key>
<true/>
<key>AutoDiscovery</key>
<false/>
<key>AutoScheduleSupport</key>
<true/>
<key>CalendarHomePath</key>
<string>/calendars/__uids__/0D06B83A-D825-4318-816C-097904CB4886/</string>
<key>CalendarProxySupport</key>
<true/>
<key>CalendarServerPrivateEventsSupport</key>
<true/>
<key>CalendarUserAddresses</key>
<array>
<string>urn:uuid:0D06B83A-D825-4318-816C-097904CB4886</string>
<string>/principals/users/<user short name>/</string>
<string>mailto:<user mailing address></string>
<string>/principals/users/<another short name>/</string>
<string>/principals/users/<another short name>/</string>
<string>/principals/__uids__/0D06B83A-D825-4318-816C-097904CB4886/</string>
</array>
<key>Color</key>
<string>#808080FF</string>
<key>Delegate</key>
<false/>
<key>DropBoxPath</key>
<string>/calendars/__uids__/0D06B83A-D825-4318-816C-097904CB4886/dropbox/</stri ng>
<key>Enabled</key>
<true/>
<key>ExpandPropertyReportSupport</key>
<true/>
<key>Expanded</key>
<true/>
<key>FullName</key>
<string><User Full Name></string>
<key>InboxAvailabilitySupport</key>
<true/>
<key>InboxPath</key>
<string>/calendars/__uids__/0D06B83A-D825-4318-816C-097904CB4886/inbox/</string >
<key>KeepOffline</key>
<false/>
<key>Kerberos</key>
<false/>
<key>Key</key>
<string>0F753F73-160F-4836-91F3-8B0A54F10B85</string>
<key>Login</key>
<string><user short name></string>
<key>ManagedAttachmentSupported</key>
<false/>
<key>NotificationCollectionPath</key>
<string>/calendars/__uids__/0D06B83A-D825-4318-816C-097904CB4886/notification/< /string>
<key>Order</key>
<integer>39</integer>
<key>OutboxPath</key>
<string>/calendars/__uids__/0D06B83A-D825-4318-816C-097904CB4886/outbox/</strin g>
<key>PrincipalURL</key>
<string>https://<server URL>:8443/principals/__uids__/0D06B83A-D825-4318-816C-097904CB4886/</string>
<key>PrivateCommentsSupport</key>
<true/>
<key>PushDisabled</key>
<false/>
<key>RefreshDate</key>
<date>2012-12-02T19:44:22Z</date>
<key>RefreshInterval</key>
<integer>900</integer>
<key>RequestCompressionSupported</key>
<false/>
<key>ShareDefaultAlarmSettings</key>
<true/>
<key>SupportsDefaultAlarms</key>
<true/>
<key>SupportsSharing</key>
<true/>
<key>SupportsSubscriptionCalendars</key>
<false/>
<key>Title</key>
<string><server name></string>
<key>Type</key>
<string>CalDAV</string>
<key>Writable</key>
<true/>
<key>isInSeparateWindow</key>
<false/>
<key>isManuallyConfigured</key>
<false/>
</dict>
</plist>
This tells me that my client is pulling this information down from the server. Annoying. Where is the configuration file on Mountain Lion Server? Why does it use the Hex address??? Short name would be infinitely better!