I don't know if I'm doing something wrong, since I'm not very computer savvy, but when I changed my settings to always block cookies from that site, there was a problem. When I clicked the vote button, it wouldn't go to the next page. It may have been just a coincidence, but when I changed the settings back, then clicked on the vote button, it went right to the next page.
I guess I'll go with the 15 minute thing.