Once the reset pin is disabled (and therefore enabled for I/O), ICSP programming won't work. I'm pretty confused with all the pin numbers, etc., specifically which ADC doesn't work, in terms of the DIP pin number?
Another thing to try is use analogRead(7) for ADC1, 8 for ADC2, 9 for ADC3.
I think analogRead(1) should be DIP pin 7, analogRead(2) DIP pin 3, and analogRead(3) DIP pin 2. Is that not what it's doing? I may give this a go tomorrow because it's starting to make me crazy now 