Thanks for that, just this very minute got it sussed, so hopefully this will help someone else out facing the same problem. BTW is appears PICkit 3 does not have the same calibration function as #2 - but will fairly accurately provide feedback of the voltage.

The issue resolves itself on both of my programmers if I force the programmer to hold the device in reset.

I did a conversion to a PIC16F88 to see if it was just the 628 playing up, however the 16F88 did the same thing so it must be something to do with my CONFIG system setup or hardware that's a bit quirky. Looking over the net there are many folks that have had the same problem, but none of the solutions I saw suggested to hold the pic into reset.

Hallelujah!!!