Hello andrew.

I think first of all bring down vcc to +5v as errik said, use pullups of 4.7k resistors, use diode in series with 470 ohm resistor ,you will have to modify the resistro value b'cse of diod's presence.If possible try diode in series with the motor wire.What about mov's?have u tried putting movs across the motor terminal?I can't guarantee u but try this things and tell what happens?