If quirky ATM machines randomly erased the accounts of 1 percent of their patrons, they'd quickly be taken out of service. Yet touch-screen electronic-voting machines that recorded no vote for 1 percent of voters in Florida's Democratic primary in March are set to be used again in nearly a quarter of the state's 67 counties. And Florida is hardly alone in switching to this relatively untested technology: 20 percent of the nation's 3,114 counties will use electronic voting machines in November. That rate of adoption alarms some experts. "We're not ready," warns Douglas W. Jones, a computer scientist at the University of Iowa in Iowa City. "I'm suspicious if we'll ever be ready."

In Florida's case, it's unlikely that one in a hundred people who went into electronic polling booths in March deliberately cast no vote, given that voters using ballots read by optical scanners -- like those used to score standardized tests -- cast far fewer so-called undervotes. But if the machines were at fault, no one will ever know for sure, since they produced no paper trail or independently auditable record. And that's one of the biggest concerns about current electronic voting technology, says Martha Mahoney, a professor of law at the University of Miami and a member of the Miami-Dade Election Reform Coalition, an activist group. The machines "lack transparency for the voter," she says. "The voter casts a ballot but doesn't see how the ballot is recorded."