Failure to sync across .mac

I am having the exact same problem - sorry I'm not providing any help on it, but I'd love to see a response and note that your question has been out there for over a month. Does anyone have any suggestions?

Hi,
I have the very same problem.
Syning iCal does not work at all, Adressbook, Keychain etc. are ok.
Very annoying!
Rudolf from Germany

I too am having the same problem - 2 Macs - a dual G5 2.5ghz and a PB G4 1.67 both running Leopard 10.5.1 - Syncs Address Book fine - meanwhile iCal no sync.. No change in the setup from when I ran Tiger and all worked flawlessly. VERY frustrating not to mention costing me $$ in errors made on relying on bad calendar data.. Apple HELP!!

I have a very similar problem, but my OS version is still Panther (10.4.11). Everything seem to sync Ok, except iCal. I tried to reset sync data. This hadn't help. Then I unregistered the computer I'm having problems with and registered it back under a different name. When the system asked me how to perform the first sync I selected “replace data on this computer”. This didn't help either. The sync engine asked the same question once, but iCal keeps asking it over and over. The unsuccessful sync attempts take very long time.

On Friday, Nov 7, everything seemed to work. In the evening I updated this computer OS to 10.4.11 and didn't use it after that. The other computer was updated to 10.4.11 like a week ago or so. In the System Preferences in the list of registered computers that are synchronized with my .Mac account I noticed some “.Mac Sync Engine”, which was not there last time I saw this screen. I tried to delete it, but it ignored my attempt.

Same problem here. I have Leopard on both machines. I keep checking for updates, hoping this gets fixed soon. The only thing I've been able to do to halfway keep synced is to subscribe to my own calendars on my macbook from my imac. That way at least I can see them while we travel during the holidays.

Have you filed a support request here using either the new chat option, or via electronic mail?

In my experience, most .Mac issues are localized or—at the very least—isolated to relatively small numbers of specific users. Waiting for an update isn't going to get it: you are going to have to actively pursue a resolution to your specific issue with a .Mac support representative.

I seem to get around the problem. My situation seems to be slightly different, because I don't have Leopard yet, but maybe it will help.

Basically what I did was that: I got to the computer that had the most recent version of data and reset sync data, replacing what was on .Mac with data from this machine. Then I got back to the other computer. It has been trying to reset its data since yesterday, but it was trying to replace data on the computer with data from .Mac. For some reason this idea didn't work for calendars. The next time it asked me what I want to do for my “first“ sync, I selected “Merge data”. It worked!

I suspect that the problem arose because I've updated my two machines to 10.4.11 at different moments. I know that the first step in solving iSync problems is to check that the synced machines have same versions of everything, which means that having different versions may cause problems.