Stepper drive problem

Have problem with stepper card not behaving.
Having tried a few other settings i am still left with problem.
I am just looking at the motor shaft not connected to machine.
When driven clockwise (Dir 0v) 3 steps can be seen clearly, and when
driven anticlock (Dir 12v in my case) it steps 1 step clock and the
other 2 anti clock thus losing 2 steps effectively.
the stepping pin is at 12v and drops to 0v when stepping occurs and
is triggered on falling edge according to data sheet, so as far as i
can guess what is happening is it is stepping clock first because the
direction pin is still 0v at this time.

I have tried all kinds of settings in Mach1 regarding pulse width,
prechange time etc ? No change.
I tried running step pin at 0v and going active high for pulse but
drive doesn't seem to respond to this.
Anyone got a good idea. maybe delay pulse some how.

Similar Drive can be found here.
http://www.alzanti.com/start.htm
PVP2435 series