Hi Joe,
Yes, that was the impression I was under. However, I still seem to be drawing around 31uA, having executed all the ideas stated in the Nick Gammon tutorial (except the reduction of the clock speed), put the radio to sleep using radio.sleep(), put the flash to sleep using flash.sleep(), and put the Moteino into powerDown mode. I have attached my code for reference (if anyone can be bothered to glance through it!).
It is all rather puzzling to be honest! Shaving off these final few uA is proving rather difficult. I feel there is something in the microcontroller that I haven't turned off properly, but I cant seem to find out what.