When hovering over a site's logo in the 'Achievements' dropdown box where your net rep change is negative, it says (emphasis mine):
You earned -5 reputation
Now, I agree that isn't wrong, but it doesn't sound right. It kind of feels like the system's mocking me (yes - it bothers me that much!).
Can it be changed to check whether the net change is -ve and if it is, then say:
You lost 5 reputation