1.2.71b has been very stable for me but the data logging problem has now appeared. The Graph view, Usage view and mini viewer show no data:
The problem may be be related to shutting down a computer on one network/adapter and starting up on another network/adapter. With 1.2.71b I stopped shutting down and restarting my computer when I changed locations. Instead, I let my laptop sleep and woke it up on the other network. This week I have gone back to restarting my laptop and the problem has reappeared the second time I did this.