Please take a look at this video: http://www.youtube.com/watch?v=x5Qb3ZfyztE.
It alleges there were some troubles for Ron Paul supporters in the elections in NY, and please expand the "about this video" section to the left of the video and take a look at the text there.
Please take a look at this as well: article \. It deals further with some troubles that people experienced.
I got both of them from BlackBoxVoting.org.