Problems with new sherline mill/camtronics system

I ordered and assembled the camtronics 2A 3 axis kit and followed the
directions to the letter and passed the tests listed. I got my
stepper motors in today from camtronics (160 oz in, 8 wire). I wired
the motors for series connection and hooked up the motors to the
board. The x-axis works perfectly, but the y-axis is behaving
strangely, when I step the y axis forward and back the stepper steps
somewhat randomly. I thought maybe the speed was set too fast, but I
lowered the speed until I could hear the individual steps and it
still doesn't work right.

BTW the rest of my config is a 13.5 V, 12 Amp switching power supply,
and the desknc software for DOS.

I double checked the wiring to the stepper motor and it looks right.

Any ideas on what to check?

thanks,
Glenn Pipe