With every incident so far reported of touch-screen vote-flipping during early voting in this year's general election --- from county to county in WV and in Nashville TN) --- it's been the ES&S iVotronic touch-screen machine that has failed, flipping votes from one candidate to another not chosen by the voter. In most instances, it's been an attempted Democratic vote, flipped to a Republican, or another party.
These are the same machines that lost 18,000 votes in Democratic-leaning Sarasota County in the 2006 U.S. House Race for Katherine Harris' old seat. The Democrat, Christine Jennings, was declared the loser to Republican Vern Buchanan (whose own wife had trouble voting for him that day), by just 369 votes. Several academic studies, and even the GAO, have been unable to rule out either tampering or hardware/software error for the disappeared 18,000 votes.