All stepper motors jutter back and foward

Hi, I have just changed my chinese prusa i3 to use a Ramps and Mega 2560 after my my melzi clone had issues. However now whenever i try to move any axis the stepper will stutter back and foward quite loudly. If i tell it to move far then it will move a few inches before going backwards and will then repeat until it stops, although the X axis doesnt seem to do this and only moves in short segments.
Does anyone know what could be causing this issue? I have put my marlin config file below.
[pastebin.com]

You haven’t install the microstepping jumpers under the pololu driver modules



3 jumpers are needed for each driver to set 1/16th micro stepping.

Thanks for the reply. I just removed the drivers and there are definetly jumpers on all of the pins.

Make sure all four wires are making good connection on the stepper motors. I've had mine just go all jittery like you explained when it looses connection to one of the 4 wires. Best way to know is to use a multimeter and ohm out the poles of the motor. If that comes back clean, your Vref might be too high or two low.

Quote
PDBeal
Make sure all four wires are making good connection on the stepper motors. I've had mine just go all jittery like you explained when it looses connection to one of the 4 wires. Best way to know is to use a multimeter and ohm out the poles of the motor. If that comes back clean, your Vref might be too high or two low.

Thanks, you were right and some of the connectors where not crimped properly Re-crimped them all and it's working great now.