Last week Windows Live Calendar got updated, the following bugs got fixed:
Syncing Calendar – You will no longer see errors resulting from a high CPU usage for the couple of minutes after the calendar sync. You’ll also see fewer error messages in general – some issues with checking for new calendar updates and meeting requests were fixed.
Shared Calendars – Some of the rules for settings got fixed – now, when you change the calendar settings for a shared calendar, it is updated for all of the other participants.
Thanks to Steve Boots for the tip.