Dave, glad you spoke up about all the improvements. I really believe the new SS7 model is practically immune to this old problem, and wouldn't want folks to get the wrong idea about the safety of the recent designs. As I said earlier, I have not heard of this problem on the SS7. When I built mine, the SS7 was still fairly new and some of these stories of the older models were still fresh in my mind, so I opted for the insurance.