Manfreds explantions of setting only the step pins to low and not the direction pins at the same time may be the solution. But due to the fact that we can free assign the pins to step and direction, the microcontroller code is not able to know which are the step pins. So we need to make a fixed assignement of step and direction pins in the jedicut configuration and the adaption to different machines may be done only by wire the microcontroller pins to the stepper board.
If all agree I would make a proposal of the fixed assignment and change the arduino code to reflect this assignement. I will then change the step mechanism to only pulse the step pin.

Martin