As the Leon County supervisor of elections, Ion Sancho's job is to make sure voting is free of fraud. Four times over the past year Sancho told computer specialists to break in to his voting system. And on all four occasions they did, changing results with what the specialists described as relatively unsophisticated hacking techniques. To Sancho, the results showed the vulnerability of voting equipment manufactured by Ohio-based Diebold Election Systems, which is used by Leon County and many other jurisdictions around the country. While electronic voting systems hold promise for improving the election process," the Government Accountability Office said in a report to Congress last year, there are still pressing concerns about "security and reliability . . . design flaws" and other issues. Election officials have repeatedly clashed with voting-machine manufacturers. A new wave of concern over today's voting technologies, started in 2003, when a Seattle-based activist named Bev Harris released thousands of Diebold documents she said she found on an unsecured portion of the company's Web site. Some computer scientists said the documents showed Diebold's systems were vulnerable to attack. Today, more than 800 jurisdictions use their technology, Harris said.