Arduino Uno Motor Shield

I have been trying to drive two motors separately using Arduino Uno and the new Arduino Uno motor shield with Flowol software but I can only get one motor to turn, it is the one connected to 1A and 1B, there is no voltage at 2A and 2B irrespective of how I program the Uno.
The Flowol software has detected the motors when it is connected to the Arduino.

Is my motor shield faulty?
Is this a problem with the software?
This is my first attempt at using an Arduino so any help/suggestions gratefully accepted.

Michael