Reputation?

I was going to send this question to a moderator but I'm unsure how so I am posting here.

I just noticed I have a -6 reputation and am confused why. I followed the link in my rep to find a post from 2011 where someone who now has a closed account gave me a bad rep for saying i was posting in the wrong forum section when it appears i was in the right one anyway. I dont know why he/she was so quick to take a stab at me but I dont feel this is deserved.

I have been a happy xmbc user for years and use the forums mainly for research but will post from time to time. Maybe im being childish but I dont want this seemingly undeserved bad reputation.

Is there anything I can do about this? Did I do something wrong 2 years ago and not realize it?