Intresting thing happened this weekend. The nodes all appeared 'down' again and yet in all screens (resources and topology) the GW was showing as up. It was a mystery. Then, I tried to turn on some lights, it worked.
So this time MyController is not getting data from the nodes, but is able to send commands to the nodes correctly. I am beyond puzzled by this as it is no longer a GW faliure nor is it a NRF24l01 lock up.