The E-Brake works perfectly well, what happens is the tire on the ground slips forward against the road. I watch it do this without turning, just skidding forward (and no it is not on gravel or sand, simple driveway dry asphalt). The simple inertia of the weight of the car on such a narrow support is what ruins the jack design and purpose.
I know you are trying to help and I appreciate it, but the jack is all but useless. God willing I wont have to use it in an emergency situation, especially on an incline.