Well if we exchange the buttons, it will be the same problem but with other buttons...
@Bosti: it is intended to lock any buttons on the screen because it's always an annoyance if things change that you didn't want to change (even switching the screen unintentionally).
Lock icon should be just for locking the start/stop button; all others should be unlocked or at least buttons like Record, Map.... because of changing displays during tranning... with new feature like "elavation profile" it happens that you switch screens at least between Map, Recorder, Navigator and Diagram... at laeast on bike... :-)