For me it was also adding just one vote, but all the bar charts on the page were for the question I just answered.

Here's the question before I answered...

And after (I had to scroll up since it seemed ok for the later poll, but the pervious polls the tallies were all for the question i answered..

These were all in the featured area. I scrolled down to the next group of polls and they all showed the same results after i voted.