This is one of the biggest problems with our system. There should be standardized and consistent voting and vote counting systems that are totally secure and leave a paper trail in every state. California went back to the old ink stamped cards, because electronic voting machines could be hacked: http://www.npr.org/templates/story/story.php?storyId=18672642
Where have we seen the worst abuses in voting? In 2004, Ohio used electronic voting machines manufactured by Diebold. The CEO was also the head of the state’s Republican party and promised that Bush would win Ohio. This year, Ohio’s Republican controlled election board chose to turn off the security systems that safeguard the integrity of the vote.