Update on the Leopard iCal Sync Bug
May 28, 2008 Update: Apple has released the Mac OS X 10.5.3 Update, which reportedly includes the fix this long-standing bug.
We've written about various issues with syncing on Leopard, but many users are still unaware of the most serious Leopard sync bug so we wanted to call it out here.
Put simply, when syncing calendars on Leopard using any sync software—including Spanning Sync—it's possible for the iCal sync program ("iCalExternalSync") to get confused and stop syncing. The primary symptom of this bug is that updated events stop appearing in iCal, but continue to show up in other synchronized devices and applications.
For example, if you use Spanning Sync to sync Google Calendar with iCal and also use iTunes to sync iCal with your iPhone, events from Google Calendar will sync to your iPhone but not to iCal. The bug is fairly rare but can affect any user at any time. And when it does strike, it continues to happen, making it appear that nothing is syncing to iCal at all.
This bug is more likely to happen when you've enabled the "Show Birthdays calendar" option in your iCal preferences. You may be able to avoid the problem simply by disabling this option in iCal.
Here's how to fix the problem:
- Quit out of iCal if it's open
- Delete the ~/Library/Calendars/Calendar Cache (where "~" refers to your home directory)
- Open iCal
- Wait about at least five minutes until *after
- it finishes "Upgrading Calendars"
- Quit out of iCal if it's open
- Open iSync (in /Applications)
- Go to preferences
- Click Reset Sync History
- Try syncing again
- Open iCal and wait a few minutes
- Create an event in iCal titled "iCal test"
- Create an event in Google Calendar called "gCal test"
- Sync
- Create a problem report ("Advanced...", "Create report") and email it to us at support@spanningsync.com along with a description of the problem.
- Consider this bug before upgrading to Leopard from Tiger
- Make frequent backups of iCal (File > Back up iCal...)
- Disable the Address Book birthday calendar if you think you might be running into the problem



Thank you thank you thank you thank you for this. I have spent the better part of this weekend trying to get my iPhone to sync up with my Entourage 2008 calendar to no avail. It just STOPPED bringing the info over! VERY frustrating.
Finally! I found your comment post over at the MacKB.com discussion and tried these steps you've mentioned here. :) It took two hours for my Entourage to repopulate calendar items into iCal and then be available for selecting in my iTunes to sync, but once it all showed up, I hit SYNC and it was good as new. :)
Thank you for sharing your experience so that I could get a bit of my sanity back before the weekend is over.
Cheers,
-Bon.
Posted by: Bon | February 10, 2008 at 05:21 PM