Quote Originally Posted by TrueMetalGeek View Post
I do most often power the PIC buy my circuit and so now that I think about it, after the first program when it starts it will have A0 and A1 as outputs (if I don't change it right away in my first program) and held low if I don't first set them as inputs or isolate them.
I also use the MCLR pin as an input rather than as MCLR. Would that be an issue? I wouldn't think so unless there is something I don't know with that.
If you don't let the pickit control VDD then there are configurations that, once programmed, can prevent the PK from being able to put the part back into programming mode.
It would have to use the VDD-first method, and that method of entry is valid only if INTOSC and internal MCLR are not selected.

Also, make sure that there is nothing on the MCLR/VPP pin that would prevent the programmer from raising it to 12V.