As a by product of my recent research, I've come across something in a service manual that might be useful if you've had something funky happen with your Panasonic cameras. This is from a GX7 manual but - like the region change boot mode - the process is common across their range so should work for all models. Not the most thrilling of discoveries but it might be useful if you have a problem and definitely would have shed some light on the Lexar card failure discussion as it will have