Several Windows XP users have complained that they've received an Outlook 2002 error message that says The MS Exchange administrator has made changes that require you to stop and restart Outlook. However, they saw the message only once. Did I do something to cause this message?

This message appeared either because you moved the users' mailboxes to another server or because you changed the default public folder store associated with the mailbox database. The reason users saw the message only once is because you made such a change only once. Once your users restarted Outlook, it read the updated public folder store value.