More than 4,000 votes vanished without a trace into a computer's overloaded memory in one North Carolina county, and about a hundred paper ballots were thrown out by mistake in another. In Texas, a county needed help from a laboratory in Canada to unlock the memory of a touch-screen machine and unearth five dozen votes. In other places, machine undercounting or overcounting of votes was a problem. Several thousand votes were mistakenly double-counted in North Carolina, Ohio, Nebraska, and Washington state. Some votes in other areas were at first credited to the wrong candidates, with one Indiana county, by some...