When I cut the lid off a box on the table saw, I end up with a step of less than 1mm on one corner, the fence is fixed tight and the blade height is set just above the thickness of the wood, it can be sanded off with my sanding board which is a sheet of MDF with sandpaper glued to it, but it would be a lot easier if it did not happen in the first place, has anyone got any advice, is it me or the saw setup