I loaded up the example sketch for the itead Motomama on my Arduino Mega ADK and I see the green led's in the middle of the board slowly going on and off as expected from the sketch. The problem is, as soon as I connect a motor, well, nothing happens and the LED's don't do anything either (on the side that I connect the motor . . . the other side works fine). I use the same motors on the official Arduino Motor Shield and it works fine (using a 12V input).
When I check the voltages comming off the screw terminals I see it going from about -6 volts to 6 volts . . . much like when I check the volts on any PWM pins.
I tried connecting the power directly to the Vin/Ground pins on the shield and got the same result.
And, I connected a BTBee to the XBee socket and added a bit of sample code to send text from the Arduino through BT back to my phone (using a test app) and that part works fine too.
There are a couple of jumpers on the other side of the screw terminals and I can't help but wonder what they do but haven't seen anything in the (sparse) docs about them.