Added and private items behave differently than all other three types of changes (Changed, Deleted, Moved). They are not really changes, actually. I think they should be separated more clearly. Now, it is not so easy to understand why Added and private items do not respond to Undo changes (http://www.plasticscm.net/index.php?/topic/1251-updated-list-of-feature-requests/) and on the other side it is easy to overlook some deleted or moved items which are listed bellow Private items (http://www.plasticscm.net/index.php?/topic/1291-some-ux-issues/#entry8989).