Have you looked at the recomodations in this document:
http://ww1.microchip.com/downloads/en/DeviceDoc/30277d.pdf
Its a old trick that if you implement ICSP on the design to include
two low value resistors in the lines.

Harry
> -----Oorspronkelijk bericht-----
> Van: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] 
> Namens Forrest W Christian
> Verzonden: zondag 10 januari 2010 10:23
> Aan: microcontroller discussion list - Public.
> Onderwerp: [PIC] re-use of PGC/PGD in a circuit.
> 
> I have a circuit where I am using a PIC18f26J11 and am quite pin
(and
> space) constrained, so I'm using the PGC and PGD (RB6/RB7) pins in
my 
> application.   These are being used as outputs from the pic and
input 
> into a 3.3V ATF22LV10.
> 
> I am programming this whole thing with a CCS ICD-U64.
> 
> Having had relatively no problems with a previous prototype 
> board, the new one was giving me fits with the programming - 
> until I pulled the ATF22LV10 out of it's socket and bent the 
> appropriate pins outward to 
> disconnect it from the programming pins.   Now everything 
> seems perfect.
> 
> I was under the impression that it was relatively safe to use 
> pgc and pgd in a circuit, provided there wasn't a lot hanging 
> off of them (I don't feel that 1 logic-level input is a lot), 
> and that they were used as outputs, and that my circuit could 
> handle the 'strangeness' of having 
> something drive those pins other than the PIC.   Which I 
> thought I had met.
> 
> Is there something obvious that I missed?
> 
> -forrest
> 
> 
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