URGENT HELP NEEDED ON CONFIGURING PARALLEL PORT CONNECTIONS FOR MACH 3

HI

I am trying to build a wood carving machine for hobbyists.The machine
has three axes all controlled by stepper motors,and for trial runs I
am using the Mach 3 CNC software.
The machine uses an Atmel AT 89S52(based on the Intel MCS51
architecture) for indexing the input om the parallel port of a PC and
the output from the micrcontroller is fed in to a SANYO STK6713BMK4
controller which is the stepper motor driver.My X and Y axis run fine
but te Z axis stepper motor's output is not as desired.the motor just
keeps vibrating and the consecutive pulses are in opposite
directions.I a m using pins 8, 9 and 14 for driving the Z axis
stepper motor circuit and the other outputs for the X and Y axes.Even
after reconnecting the Z axis controller's connections to different
pins (2,3,4) of the parallel port of the PC,the same problems
persists.The port pins of the parallel port were configure correctly
using the MACH 3 SOFTWARE and te motor was tuned to run at 40 freq/rev
and with an engine frequency of 25kHz.Te stepper motor works fine with
other control circuits and the controller also works fine wit a
standalone circuit.

I require some urgent help in solving this problem I am facing as all
other components of the machine are working fine.
Looking forward to a early reply
thanking you
HARSAVARDHAN