I have a PICSTART plus which I use principally to program
16F84's. Until now I have NOT been programming in circuit.
Today I have added a 5 lead ISP lead to a new PCB design and
tried in circuit programming. It works, BUT.

The system will program and declare success on the verify
which occurs immediately after programming but will fail on
subsequent verifies. If I take the PIC out of the PCB and
place it in the programmer it will verify OK.

Summary:
          - ISP programming works properly
          - Verifying immediately after programming works OK
          - Verifying subsequently fails.

I could get all keen with an oscilloscope and several
(many?) hours of interesting investigation (and probably not
learn anything :-)) but, perhaps, someone has
been-here-done-this already and will be able to advise me of
what may be wrong. Wiring length is about 200mm (8 inches)
using discrete wires. I have spread these apart and had them
together with no change in results

POTENTIALLY RELEVANT INFORMATION:

MPLAB is 3.22.02 (21 May 1997)
The PICSTART plus reports version 1.20.00 when it
initialises.
(The "HELP" screen in MPLAB mentions the version 1.30.00
programmer)

I have 22K on the reset (MCLR) lead to an anti brownout cct
(pnp transistor switched to Vcc) and 10K on port B7 to a
capacitor. B6 drives a ULN2803 directly which has (as I
recall) about 4k7 internal resistor. This means that MCLR
and B7 effectively have a 10K load and B6 a lower load.

I can't RTFM on the hardware for the programmer as the
manual has gone to where-ever manuals go when they see you
looking for them (presuming that one came with the system).