I just bought a starter kit and a motor shield, In code when i call the Initialize method on the Motor Driver, my motors start moving erratically.
Have you put caps on your motor to reduce noise?
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No caps… I am using a 6V supply to power the Domino and when i copied the sample code provided in the brochure The motor initially moves erratic and then settles down.
The first time I hooked up my motor component(stand alone one), it did the same thing and heated the IC on the motor board.
My problem was that my motors were too big for the motor board.
What are the specs for your motors. Are they more than 1 amp?
Mike in MN
I am using Mabuchi FA-130 Motor
Operating voltage 1.5VDC to 3VDC. At 1.5VDC no load output is 9100RPM at 200mA, stall torque is 26g-cm (0.36oz-in) at 2.2A and maximum efficiency output is 6990RPM delivering 6g-cm (0.08oz-in) torque while drawing 660mA current.
I did figure out one thing… If i power the Motor shield externally It seems to work most of the time, but still not perfect… What kind of motor are you using?
I am using:
HTI HTRRR04206705B-0001
RS-550PF
After looking up the sheets, it says that current is 1.0A to 1.3A, too much for my board.
Does the IC get hot on the board. After reading alot on the forum here, it is always recommended to use an isolated power supply for your motors.
As a note, I did play with it a bit, they always started out jittery, but once they got going they were fine. I suppose at startup they need more current and the board couldn’t deliver it.
Mike in MN
Hey Mike… I took a second look at my motor specs and it seems it can draw upto 2.2A … I have ordered lower amped motors… Hope to see some better results… 
… Thanks for the help.