Segway Inc. is recalling all 23,500 of the self-balancing scooters it has shipped to date because of a software glitch that can make its wheels unexpectedly reverse direction, causing riders to fall off -- and in at least one incident, break some teeth. The U.S. Consumer Product Safety Commission, with whom Segway is cooperating on the voluntary recall announced Thursday, said consumers should stop using the vehicles immediately. Segway has received six reports of problems with the Personal Transporter, resulting in head and wrist injuries. The vehicles were previously known as the Human Transporter. Segway is offering a free software...