This can be seen on [my reputation page][1]:

This sequence resulted in a 10 points reputation loss:

    	 12 mins ago	upvote	Javascript load images in canvas with JCanvaScript
    -10	 12 mins ago	unupvote	Javascript load images in canvas with JCanvaScript

(Unupvote is first)

Why? Is that a bug as I imagine?

  [1]: http://stackoverflow.com/users/263525/dystroy?tab=reputation