Ok thanks jdww for the feedback, I managed to salvage my corrupt SD card by copying the contents to a new SD card, amazingly this worked, saving me the effort of setting up again. I don't have a heat sink but with the old March build running I can put my finger on the cpu and it's hardly warm, unlike the latest nightly where it was burning hot. Living in a hot climate the temperature is a real concern!
Anyway, Netflix is up and running again, and the family is happy once more. That's the main thing.
I am going to have a look for the source on github and see if I can find the reason it's heating up for me, if I have time. Not sure if my laptop has the resources to build this whole project from source, though!