I got this:
You last voted on this answer Feb 8 '11 at 16:40 Your vote is now locked in unless this answer is edited (click on this box to dismiss)
So this was shown to me on stackoverflow. I tried to remove an upvote to an already downvoted answer, I did not see that that the answer was really flawed. Another commenter saw this and responded. I wanted to take of my +1 (the tally was -1) so it would be a -2 which would mean more to visitors in my opinion.
I guess what I'm trying to say here is that a comment from somebody else other than the author (who clearly didn't take the downvotes as a hint) might influence my opinion.
This question is slightly different because the assumption is that your comment is picked up by the editor of the question. Should votes be unlocked after comments, not just edits?