i keep getting those nasty stepper buzz sounds once in a while on rapids that lock up steppers so i loose coordinates. I scaled back on rapids in Mach 3 to 65ipm for X/Y and 60ipm for Z and still once in a blue moon Z freezes doing rapids (especially going up). How can I fight with it? I see some machines accelerate their rapids to 100ipm or so and doing just fine while mine backfires on me even with much slower rapids. Can that be because of the axis acceleration values in Mach3? The problem is that it is hard to tell what change leads to what result since "freeze" happens occasionally and is not reproducable on demand.