users share calendars of other employees for scheduling. After Migrating from Exchange 2003 to Exchange 2010, the users cannot click on other users calendars to open. they have to manually select "open shared calendar" and type the users in again even though there are shortcuts on the left pane. If you try to click users calendar in left pane, it will error and say lost connection to Exchange server. the only possible change is that we took them out of the Cached mode because it is not a traveling pc.