I'm not the person who downvoted you, but I do think you're mistaken. If you think it should be a top level post, the parent and grandparent both tell you to take the same action. The problem with Dorrika's poll is that it tells the number of people who want this to be a top level post, but not the number who don't.

Also, if you "upvote a post twice" it winds up not doing anything because a second click of the "vote up" button undoes the first one.

Incidentally, if the person who downvoted this did so because I'm mistaken, I would appreciate being corrected explicitly... I still can't see the flaw in what I said.

(If it's for other reasons, that's perfectly fine and doesn't require further explanation or discussion.)

The point of the karma balance post is so that its karma is the opposite of the poll's karma.

It is a karma sink, not a balancer that must be equal but opposite. It is a way to short out people's desires to not reward karma for privilege of providing information, or a way to penalize the poll itself without damaging the data. Since we wouldn't gain information by having two copies of the same number there is no real need for the karma sink in sync.

What does seem to be a problem here is that your poll comment is (or rather was) negative. Your poll comment should never get a downvote, ever, if people are cooperating in the poll game. Downvoting defeats the purpose of having two separate comments for 'be top level' and "don't be top level". This just means that the downvoter has chosen not to submit to demands (or acquiesced with the request) to vote according to the prescribed pattern for these particular comments. They aren't cooperating within the poller's game. Unfortunately it is not possible to know how many people have just chosen not to play so all such votes corrupt the data rather significantly.

This is where having an explicit poll mechanic would be rather handy.