Most blades have a burr on the right side, to stay on the line move the wood some degree to the right, this helps to, stay on the line. You might not have enough tension on the blade, the blade should not move sideways more than 1/8" and that is almost to much. When the blade is grabbing the wood, this means that you have not enough speed and you are pushing too hard into the blade. Let the blad do the cutting.
FD Mike