I yapped about this on some earlier thread.
Here's an idea of how my thread ended up as a four star, when it should be a three. I know a mod could get the full readout of the people who''ve overrated my thread, but still.
I have no idea who the first person to overrate my thread was, but when there was only one vote, it's easy to fix. And that's what I did. I downvoted it myself so it would average into a three. But then every once in a while I'd get a post like this.
But over time it got to the point where I can no longer fix the rating with a single vote.