Did you vote on site one then forget to vote on site two and it ended up being forty minutes? They're counted separately so voting on site one at 3:30 and site two at 4:10 will make the next vote time for site one at 9:30 and voting site two at 10:10. If that makes sense.
In short, you probably just forgot to vote on site two for a while. Just wait for site two to catch up with site one and you can vote on them at the same time again.