Do you really believe that a person could go into a voting booth, open up the locked and sealed voting machine, connect a motherboard to the circuit board in the machine, re-lock and reseal the machine, all without being noticed?
I still think it would be much easier to "stuff" a paper ballot box, something that has been going on for centuries. Washington State is notorious for cheating with paper ballots. No matter what system we use, if the people counting the votes are corrupt, the election will be corrupted.
With all the "electioneering" I saw going on at my polling place in 2008, I'd not be surprised to learn that some people are being paid NOT to notice.