So, just for the sake of completeness, new batteries made no difference at all. I have gotten a few trouble-free tanks and even batteries worth of Radius use in the days since I first posted this, but the wonkiness continues. It's hard to describe, but the thing just seems to be constantly rebooting itself at random. Even when I'm not even touching it, after a good cleaning, and with a fully charged brand new battery installed and a coil/voltage combo that is nowhere near it's rated capacity. It's taken one tumble too many last year, I guess. The only thing I haven't tried yet is reflashing the firmware and I don't really see what that could possibly do. I'm pretty sad that it's become so unreliable. I don't even take it with me when I leave the house anymore since I have no idea if/when it will decide to fire. I don't think I will bother repairing it because I'm not too confident that this won't become a yearly occurrence. It's become just another mod that couldn't make it past one year without dying. I have really bad luck with these gadgets. I kill them all really quickly.