Doubts over voting machines cloud Obama's S.Carolina win

In the U.S. presidential race, Barack Obama has won a big victory in South Carolina's Democratic primary. With huge support among black voters, Obama won twice as many votes as runner-up Hillary Clinton. While the results are not in doubt, come critics complain about the way votes are counted. They say the U.S. continues to use inaccurate and unreliable voting machines. Diebold claims only errors are by humans.