sent in a regrade request 2 days after the exam, and i just recieved a letter in the mail saying that there was indeed an error. I was refunded the testing and registration fee, and they apologized for the problem. It was due to the fact that I had somehow managed to get my answer sheet wet during the exam. And for the record there have been changes made in the past for scores, but it is very very rare. I know an individual 3 years ago who actually recieved 3 points after a regrade, and there have also been people who have lost points as well.