The trials and tribulations of electronic voting are not just an American problem. The Dutch Government apparently had their main supplier of e-voting systems essentially threaten them with blackmail if they didn't purchase his company after an independent watchdog group (great: The "We don't trust voting computers foundation") leader was poised to be put on a commission to investigate the voting computers.

This kind of problem isn't really specific to e-voting, but it does make a good argument for open-source e-voting systems. If the source is publicly owned and maintained by government programmers (doing releases and testing for elections) plus the open-source community, your blackmail and sole-source problems go away.