Every Vote Counts, Except The Ones You Cancel Out

You've probably already seen this e-mail that's been making the rounds, a warning from the ominously named Committee of Seventy:

If you first push the button for the presidential candidate you want and then push the straight party button, you will cancel out your vote for president on the voting machines used in Philadelphia.  This is because it will be as if you had pushed the presidential nominee's button twice: the first time selecting him and the second time unselecting him.  If you want to vote the straight party ticket, just push that button and it will include that party's nominee for president.  If you want to select a nominee for president individually then you need to select all of your candidates individually.