Well, two sites does not make a pattern, but it certainly sounds suspicious. If you can reproduce it by doing whatever sequence of events happened on those machines that would help. Obviously you don't need to let it "sit" for 10 hours, just do the sequence and see if you get the problem. Or better, don't make a point of voting on all the machines, and see if the zero ones have the same problem tomorrow. Since there are no votes, this is harmless.