Well the problem all along i reckon was the header pin of J101 - replaced these and it worked fine.  I reckon i was getting some of the AC readings as when i put one of the leads on pin 1 (which was tarnished) it might have just put enough pressure on it to get a reading - yet when i do a DC reading, there is no pressure on the AC input pins....dunno - just my thoughts.

Interestingly, the voltage is only 4.88 - even after jumpering everything and replacing all bridges and caps. From what i understand, the voltage regulators have a fairly wide range of operating specs, which is why i've tended to put a 22ohm resistor between the voltage regulator and GND to bump the output up a bit (normally to around 5.03v).  I'll leave this one as is for a while and see if there are any reset problems (which i suspect there will be with only 4.88)

Thanks heaps for the help

Rob