(FORTUNE Magazine) – Dear Annie: I recently had my annual performance evaluation, and it came as a complete shock. The manager made a huge issue out of two minor incidents, even though both were resolved months ago to everyone's satisfaction. The evaluation contains factual errors and is grossly unfair. Do I have to sign it? --Maligned

Dear Maligned: "Your signature doesn't necessarily mean that you agree with the evaluation, but rather that your boss went over it with you and you're aware of the contents," says Scott Cohen, Ph.D., national practice leader of talent management at Watson Wyatt Worldwide. Pick up the phone and talk to someone in human resources about what people where you work usually do in these circumstances. Do they refuse to sign? Sign, but attach a letter of protest? "There is no consistent policy from one company to another, so ask," Cohen suggests. "And do it in a conversation, rather than by e-mail or by writing a letter. A letter always looks as if you're arming for battle, and right now you're just seeking guidance. Going over your boss's head to complain to another boss would be a mistake, but handling these kinds of issues is the reason companies have HR departments." One other thought: A performance evaluation should never come as a complete surprise. Cohen recommends that once the smoke has cleared, you have a little talk with your boss about the possibility of getting more feedback between formal reviews. If he's so unhappy with your work, wouldn't you rather know it sooner than later?