In my experience, the way that most curves work is that the standard grading system usually falls within the curve, and if it doesn't it's to the student's benefit. For example, in my Organic chemistry class, >84 was an A. On a standard grading scale, >90% is an A. Thus, the curve could only help you. I've never encountered an instance where the curve actually hurt you, especially in classes like organic chemistry or biochemistry where class exam averages frequently fall below the 60% line. Usually a curve is utilized with low class averages. I can see where it COULD hurt you if everyone was scoring 85% on their exams.
I have heard of an instance where the curve was hurting students. A girl in my genetics lecture was telling me how you had to score over 100% in her general physics lecture to get an A because of the curve. In that case, it's just not fair.
I guess since you're posting this you've been the victim of an unfair curve. In that case, I would first talk to your professor. When a professor at my university decides to use a curve system, usually a student speaks up the first day of class and asks "Is it possible that we can score >90% but still get a B"? Usually they'll say no. If that fails, talk to the administration of whatever department your professor is in. Maybe they'll be able to do something.
