ghost in the x axis - bad electrical connection

[jonm]

hi
in mach 3 if i jog the x axis in the + direction then stop , then jog again in the in the + direction , some times the axis goes the opposite way but the dro is still incrementing in the + direction , anyone any ideas

also does the same when cutting , disconnected the motor from the screw so as there is no load and it still does it