to be fair, those machines use an older method of touch screens, where an overlay registers your touch and corresponds it to coordinates on-screen. If that's out of whack (which about the only way it would be is if it were never calibrated at the factory) then something similar would happen. Basically, in this video his touch was off by about 4" vertically. When he pushed Obama, it thought he pushed something 4" lower. When he pushed Straight Democrat, same thing happened, whatever was 4" below was what got pushed.

So, if you find that happening to you, just press 4" above the selection you want. It looks like you'll have as much time to fiddle as you want to get it right before you push the big red "vote" button at the top of the screen.