[geekmaster]

Hmm, I just connected USB to computer again while PW3 desktop working. It popped into an out of "USB Charger" mode detected on PC, touchscreen not responding, reboot half a minute later. I think I see a pattern here -- perhaps it is reformatting /mnt/us (and copying the "welcome" document there). That may indicate data corruption on the userstore partition (or a glitch from bad firmware or bad rootfs), or a power problem that affects flash or SD-RAM reliability... Or a bad connection somewhere (like that hall-effect sensor -- but should that corrupt userstore?)... That could also be why it switches to "Charger" mode (which is "0MB flash drive" mode on earlier kindles) when it tries to switch to USBMS mode.

EDIT: It is still in airplane mode though, even after losing the system log documents, so apparently /var/local is NOT getting reformatted... I just deleted "Set Up Your Kindle" -- to see if it comes back after reformatting (if that is indeed what is happening). [Nope, that is not it. After moving USB from PC to power supply, it reboots again. Empty documents folder... Still, it seems intuitively related to loading the mass storage kernel module...

EDIT2: That "Lab126, Inc. USB Charger" mode is USB VID/PID 1949:DEAD, which probably means "dead battery" (the "charger" mode that virtualbox calls it). Less scary than a dead device...