Z-Wave network had been running well, but after adding some more switches the stick would go unresponsive and needing to restart the add-on nearly daily, Finally decided to update the firmware, the PC Suite said NVM backup was not supported, and after upgrade found that it had lost all the devices.
So now need to build the network again.
ZWave is really a frustrating solution. Part of my network is on Vera and I have that controller automatically power-cycling every night to keep it somewhat functional.