I apologize in advance for bringing this issue to the notice of the community. However, I found this instance of downvoting to be quite irregular, and I wanted to "flag" it, by bringing out the issue here.
So, here's the problem. I answered this question, and this was certainly a "correct" answer. However, an user downvoted the answer, and later admitted in comments in the same thread that he downvoted the answer, as he wanted his reputation to be divisible by 2. Now, I don't think that's the right way to implement one's right of voting, and hence I wanted to bring the issue in front of the community.
( I certainly appreciate the honesty of the user, and I don't care too much about my own reputation, except that I am morally against the wrong use of voting. )