How common is this problem? You don't use your saw for a month or so and it takes a few cuts to smooth out. My delta has three belts on a 3 pulley sheave, so imo it's more pronounced than a saw with only one belt. Now don't get me wrong I can stand a nickel on its side when running and a dime in certain areas, so it runs pretty smooth, just has a little more vibration in the beginning. It probably has the original belts from 2003 and could just use a fresh set, but they don't slip so I don't worry about it.