thinkign about it some more, i am starting to suspect the ignition switch. the other night, i turned the car off and the radio turned off. then later, my son said he heard the radio in the car playing and he turned it off.
sometimes the radio would turn off when i took the key out, but now (or at least for the moment) it stays on.
I also needed to replace the key-lock cylinder thing, so I did that tonight. Unfortunately, that did not solve it. Adam, were you talking about the key lock thing, or the switch part that the end of the key lock thing goes into?
found it! the wiring for the radio was all screwey from whoever put the radio in that was there when i bought the car.
long story short, there is a green/yellow wire that is always hot, and a yellow/black that is keyed. those 2 wires were deliberately shorted with a paper clip that was all taped over. once i removed that, now the clock and radio are only on when the key is in, just like it is supposed to be.
the wiring is still pretty screwey, but it is better ... i have more to do there.
adam, thanks for offering your ignition switch, but i don't think i need it any more.