I didn't vote you down, but I find it completely unnecessary to write an apology and it's a little annoying to read one for a mistaken downvote, as this adds nothing to the discussion. It's just a mistake. It happens. The voting is anonymous (to all except pg and a few others perhaps). If you want to apologize, try to find a way to send a private message. I'd say you got downvoted for cluttering up the discussion, which ironically I am now also doing. Oh well, hope this helps anyway.