CPU is being consumed by external syncing, and deleting all subscribed or local calendars is undone a few moments later as it is reinstated. I've checked permissions, removed the cache and let iCal 'upgrade' the file. I've restored the iCal app itself from the Leopard DVD. The ~/User/Library/Calendars/ folder has continuous activity This is only stopped by a reboot and avoiding iCal. Any thoughts anyone? **Edit** Deleted externally synching calendars and in the 30 seconds before they reappear, I did a backup. I then restored this backup and all is good - took a couple of goes to fit in the plan but the result is good.