I am not sure what is going on but my G29 is screwy and I only just found it out. I can do a G28 or even a G30 but only with G29 does this happen. What happens is it will go scanning my bed then finish. Alright, but from then on any direction I tell the head to move, via pronterface, makes all axis move simultaneously by that much. When I do a G28, or a G30, the issue disappears. Almost acts as if something is left on that shouldn't be. Any ideas what is going on?