Voting machines were voting Obama when Romney was selected. That was all over the place. How many votes was that?
Please be more specific. What type of technology regarding the voting machines are we talking about? Electronic touch screens? Or something else?
Also, in what states do you know of complaints along these lines? I know this happened in Colorado during early voting, but haven't seen articles about other specific instances - yet.
I saw that Allan West's people are complaining about voting irregularities in Florida, where he is down by 2400 votes, though absentees (including a lot of military, I'd assume) haven't come in yet.
Most people wouldn't notice. When they get to the end, they just hit enter and leave without a thought. Just like most people don't bother checking their reciepts at the grocery store. They "assume" it's right, sign their name and are out the door. There's no way of knowing what happened once the votes got into the system and were counted.