Dennis,

With a few well place diodes you should not have any trouble with
doing an in circuit programming.  You may want to make sure that
your oscillator is off while programming.  I had trouble with
it incrementing the program locations.  So instead of starting a
0x0000, the program would load randomly from 0x0001 to 0x0010.
Once I disabled the oscillator, everything worked great.  I think
that you should still be able to use your picstart.  If you can't,
you could always build David Taite's programmer.

Good luck.

Yours,
--
Derrick Early
early@finite.nrl.navy.mil