Arduino Motor Shield R3 stepper motor

I am trying to drive a 4 wire stepper motor from the Galileo via an Arduino Motor Shield R3.

I have used the same motor with the Arduino Motor Shield installed onto an Arduino Uno R3.

I noted that sometimes I saw a "trace error 9" message on the console when the sketch loads.

With the Arduino/Arduino setup I can observe a square wave on pins 12 and 13 of the shield using a logic analyzer.

With the Galileo/Arduino combo there is no output on these pins. I was able to confirm pin 13 is able to change by running the blink example

and looking at that with the logic analyzer.

The example code I am using is identical, but run in the appropriate version of the Arduino IDE.

I notice the same shield was used for the on line course by

Nicolas Vailliet but not with stepper motors.

Any suggestions appreciated

thanks

Nigel Smith