Following a freak install problem in which I still can't determine what went wrong, my Rio has lost the ability to determine if the accessory power is on or not - it is just on constantly (tested in my other car)

I am still not sure what the install problem was. I was installing into a 1995 Mitsubishi Eclipse. I have installed my Rio in about 5 different cars before with no problems. I wired as usual, and after the Rio booted up, first was silence... then the amplifier produced a deafening sound through the speakers that was most definately not the music. I pulled the plug as quickly as possible, but the Rio was damaged. Why the switched power sense circuit was damaged I do not know - the car wire I used worked fine as an amp turn-on lead before the Rio was in the car.

What could have caused the switched power sensing circuit to fry? I need to know what happened before I try to reinstall or install another stereo. Could this have been a remote turn-on problem with the amp?

The amp didn't fare as well - after hooking up my walkman again, magic smoke was released about 5 minutes later.

Thanks for any and all suggestions you may have. I'd also like to fix my Rio, but I doubt it will be feasible.