I have a part-time job that I mostly do from home. There is a fairly new guy at work that handles some of the computer/technical stuff. To make a long story short, I do about 95% of each task and this guy is responsible for the other 5%. The thing is, he is routinely screwing up the other 5% - to the point where it is affecting my income (not a lot, but a small amount). Since he is fairly new, I have cut him some slack, but the careless mistakes continue and I finally mentioned something to my boss. It's not like I threw him under the bus, but I let my boss know that things have not been running as smoothly as perhaps they could be. Well, yesterday and today, I have dealt with yet another bunch of mistakes and I'm sooooooooo irritated. What would you do? Address it with him? Go right to your boss? I don't want to get the guy fired (or maybe I do if he can't do his job properly), but something has got to change.