What I have found out about the bed of my mill is that it is warped. Because of this it was imposable to lap it and get it to run smoother and with-out side play. So the fix is to re-machine the ways and true the top surface. So if you have a HF mill you may have to do the same. I also found out that the dovetails were not cut the 60 deg they should to be, because of that the gib would not sit true. I also replaced the stock gibs with a brass one which really smooth out the movement.