DVK's answer is correct. The asker even commented thanking DVK. We all know it is the answer. But the asker forgot to accept it (the "check" button), and this is one of those users that doesn't seem will ever come back to the site (last seen: December 2012, just to make the only question he/she ever made).
It of course makes sense if the asker is the only one who can accept answers, but in this kind of situation it isn't very nice when everyone knows that the asker already acknowledged that the given answer is correct.
Is there something we should do about it? Can a moderator accept the answer etc?
Ya know, there is this itch you feel when you see something that should be some way but, well, it isn't :P