Sean Breheny wrote:
> Can someone please explain why a resistor is needed and how it could matter
> where it was placed?
>
> I could see that the resistor will limit the current which is charging up
> the gate,but how this would be likely to hurt either the PIC or the FET I
> don't really understand.

It may disturb a read-modify-write instruction in the software.  If the
code pulls it high then low and is read fast, the pin still stay charged
due to gate capacitance and the pic may read it as 1 and the FET may
remain on.  With a resistor in series, this problem is minimized.  The
use of shadow register can eliminate this problem.

regards,
Reggie