If the bow shoots sweet and is accurate then I would leave it. Sounds like its just getting shot in and you are seeing the how the bow reacted to the shooting. Often bows do need a little touch up after they have been tillered. Usually I'm carrying a scraper with me when I shoot in a new bow, and am making subtle adjustments to the tiller as I put arrows through it. My feeling is a bow with 500 shots is barely broken in, when over a lifetime hopefully it may take 100,000 + shots, and the break-in process is often longer than most realize..