Spam attack & negative reputation given

[Black Guard]

Hey, someone joined my forum (now banned) and posted spam, then gave me negative reputation, twice. I'm an admin, but I can't seem to fix the reputation back up. Also, is there a plugin that tells you the name of who's given you reputation, because it didn't display the username, only:

'comment given: "your a meany"' - the spammer.

Thanks again.