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 quirk, misallocating several hundred votes for Democrats to Libertarians. In Florida, some machines temporarily indicated votes intended for challenger John F. Kerry were for President Bush, and vice versa.
In the month since the election, serious instances of voting machine problems or human errors in ballot counts have been documented in at least a dozen states, each involving from scores of ballots to as many as 12,000 votes, as in a North Carolina county...local officials discovered problems and corrected final counts. In some cases, the changes altered the outcomes of local races. But in North Carolina, the problems were so serious that the state may hold a rare second vote..
Since 2000, watchdog groups have intensified their monitoring and cataloging of complaints and errors. The nonpartisan Verified Voting Foundation and other groups built a database of more than 30,000 ‘’election incidents” reported across the country this year. Most were routine, but nearly 900 involved significant e-voting problems, including malfunctions that shut down machines, lengthening waits at the polls. There were 42 reports of total breakdowns of machines in New Orleans and 28 in Philadelphia and ‘’15 reports of catastrophic machine failure” in Mercer County, Pa. [http://archive.boston.com/news/nation/articles/2004/12/01/voting_errors_tallied_nationwide?pg=full]
See also, “THIS DAY IN HISTORY: Election results between Al Gore and George Bush too close to call” [https://www.history.com/this-day-in-history/presidential-election-al-gore-george-bush-too-close-to-call On December 12 Gore conceded to Bush]