US voters calling in to a toll-free number had reported more than 1,100 separate incidents of problems with electronic voting machines and other voting technologies by late Tuesday during the nationwide US election.

In more than 30 reported cases, when voters reviewed their choices before finalizing them, an electronic voting machine indicated they had voted for a different candidate.

E-voting backers called the number of reported problems "minor" in the context of almost 50 million US voters projected to use e-voting machines on Tuesday.

In the majority of cases where machines allegedly recorded a wrong vote, votes were taken away from Democratic presidential candidate John Kerry, or a Democratic candidate in another race, and given to Republican President George Bush or another Republican candidate, said Cindy Cohn, legal director of the Electronic Frontier Foundation (EFF).

In all the cases of misrecorded votes reported to, the voters were able to change their votes back to the candidates they wanted before casting the final ballot, Cohn said. But in some cases, voters had to correct their ballots multiple times, and in other cases, voters may not have noticed that their votes were miscast, Cohn said.

"We're only hearing from people who caught it," Cohn said during a press conference hosted by a coalition of nonpartisan groups that have questioned the security of e-voting machines. "It gives us this uneasy feeling we're seeing the tip of the iceberg."

The reports of misvoting happened on a variety of brands of e-voting machines, Cohn said. In some cases, e-voting machines may have misread voter intentions when the voter accidentally brushed the computer touch screen, she said.

The Information Technology Association of America (ITAA), representing e-voting machine vendors, called the number of reported e-voting problems insignificant compared to the millions of voters using the systems during Tuesday's election.

Unlike with some other voting systems, such as paper ballots, voters using e-voting machines were able to catch misvotes before casting their ballots, said Bob Cohen, senior vice president at ITAA. "The machines helped them catch the error," Cohen said in response to the reports. "With other forms of equipment, that probably can't happen. It's a great credit to the technology."

But Doherty and other e-voting critics watching the growing number of incidents suggested that only a small fraction of voters with problems reported them to It may be a number of days before e-voting critics know the extent of the problems, said Ed Felten, a Princeton University computer science professor.

Voters may not know for days about problems such as voting machine numbers not matching the number of voters counted at a precinct, Felten said. E-voting critics may file open-records requests after the election to look for those types of problems, Cohn said.

"The problems I, for one, worry about are the problems that are not yet evident," Felten said.