SOUTH Africa is back at work and functioning on Tuesday after Y2K fears proved a total dud. The Johannesburg Stock Exchange opened without a hitch — mirroring markets around the world. The market surged in early trade in what dealers say is sheer relief that the much-feared Y2K was a no-show. In its round-up the Y2K Centre reports that automated teller machines, airplanes, military systems, and other highly technologically dependent devices continued to operate as if nothing changed.