mmm, interesting link but, sorry Alain, to me wasting my time (based on >50$/Hour) for a <2$ device is a real money waste... even with the recent things that happened...

If you lost your OSC calibration it might mean that you overlooked your PIC programmer options.. or simply it's a freeware. With any of the previous, the first sentence apply. BTW, if you don't need anything timing critical, even with a stupid RC osc, just don't recall it and it will work.