Troubleshooting forever

I wasted like over two hours just trying to DO WHAT I DID again. It works great... EXCEPT that when the motor is plugged IN, the ultrasonic rangefinder starts getting some bum values every few lines, meaning that it no longer works the way it needs to at all! The motor and lights twitch even when no one is standing in front of them! It makes me so mad!

I have no idea at all why this is happening. The code is the same. The wiring is the same. The parts are the same. I know it's the motor, because it works fine when the motor is unplugged. But why??? WHY HAVE THE SENSOR GODS FORSAKEN ME?

I'm going to ask for help on monday and see if i'm missing something obvious. I mean we can still have moving motors, which is good. I also wanted to try and get a piezo disk to work but I don't have time for that right now. LAME.