My Team has a Group Calendar in the Public folders on our exchange server. As we did with Outlook 2003, we add the Group Calendar to our Favorites and it "shows up" under Other Calendars. However, everyone who has or has upgraded to, Outlook 2007 is experiencing a common issue where the Group Calendar mysteriously and periodically disappears from the "other calendar" list. Further, many are then subsequently experiencing issues getting the calendar to show back up after adding it again to the Favorites. some of the laptops were existing computers updated with Office 2007, while others are new computers that have only ever had Office 2007. What are we doing incorrectly?