>If I take an identically programmed pic and circuit, duplicating
everything
>except the shared power supply; I get a problem. Instead of each PIC
>responding independently to touch on - they both respond to the same
single
>touch on either PIC.


Sounds like your touch circuit needs work.
Is V- actually earth grounded?
Without knowing which way you are detecting "touch", it's hard to say.
It looks like the touch on plate A is bouncing the ground, such that
it looks like another touch occurs on plate B.