Electronic voting has made great strides in reliability, but it has a long way to go. When reformers push for greater safeguards, they often argue that future elections could produce the wrong result because of a computer glitch or be stolen through malicious software. That’s being too nice.

There have already been elections in which it is impossible to be certain that the right candidate was declared the winner. Here are three such races. It is not just remarkable that these elections were run so badly, but also that the flaws are still common  and could easily create havoc in this fall’s voting.

1. The 2002 Georgia Senate and Governor Races  Senator Max Cleland, who lost three limbs in Vietnam, was defeated for re-election and Gov. Roy Barnes, a Democrat, was unseated. Polls had suggested that both men would win.

The votes were cast on Diebold A.T.M.-style machines. A whistle-blower who helped prepare the machines reported that secret “patches”  software intended to fix glitches  were installed late in the process without being certified by the state, as the law required.