msd has an issue with that. the alternator will continue to power the switched side of the wiring. install a diode on the field wire. this article discusses older versions but i've had problems with hei doing the same thing. http://www.msdignition.com/page.aspx?id=3296
Then it makes me think what the previous owner did before....How did he turn the car off? Is this a type of problem that just starts to happen overtime? Ill get a diode tomorrow and see what happens.