I don't have the book or schematic in front of me, but from the pictures it looks like you're wiring the motor directly to the power. You have the hot/red wire directly connected to the right-side power strip (assuming that the 9v supply is attached at the top) and you have the black connecting through the diode to ground. Where's the "switch" to turn that off?
EDIT (6/1/13)
Am now at home, looking at the diagram it seems that the diode goes to the positive bus, not the negative bus as your picture shows...