I would remove the shorting link and replace L5 (which I found to be
very fragile) with something from the junk box directly between Pins 7
and 20. As it's purpose is to keep digital noise out of the analogue
circuitry, anything from 47uH to 270uH will do, it is not a critical
value component.
This 'Unreliable microcontroller start-up at power-on' modification is
documented on the website, refer to that and take whatever action you
feel appropriate.
