Int'mit wrong direction

Trying to get a new machine working.
No Y movement at all, but I just saw a post about Arduino 1.0.6 needed to upgrade firmware 2.1.1.
Hopefully that will fix Y.
When stepping manually I Intermittently get movement in the wrong direction.
Both X and Y motors display this behavior when driven by X drive circuit.
I changed X and Y driver circuits (testing the Y problem) but reverse problem no change.
Hand moving seems smooth and easy. Voltages .44’ish
I’ll try a bit of oil.
I suspect it is skipping a step and getting the drive pulses out of order causing a reverse.
Would this be a possible cause?
Driving X and Y motors with Z driver gives good long runs without any signs of trouble.
I haven’t tested X and Y motors enough on the Z drive for the reversing yet.
Surely the motors are wired correctly. I don’t want to open the shrink plastic if I can avoid it.
Thanks in adv

It is likely that your motors skip setps.
Try setting your stepper drivers to 0.55v.
That works better.

cheers,

Christian