This is the Paperwhite first gen with latest 5.4.4 update and latest jailbreak.
I plug the Kindle, it shows "USB Drive Mode" and then after some seconds the kindle restarts itself.
The computer sees the kindle, Calibre sees the kindle, and when it restarts, the computer stops seeing the kindle.
If USB Networking is enabled it doesn't enable "USB Drive Mode", but the kindle reboots after some seconds. I can even connect to SSH before it dies, but the SSH session always dies. And the kindle restarts.
I plug the Kindle, it shows "USB Drive Mode" and then after some seconds the kindle restarts itself.
The computer sees the kindle, Calibre sees the kindle, and when it restarts, the computer stops seeing the kindle.
If USB Networking is enabled it doesn't enable "USB Drive Mode", but the kindle reboots after some seconds. I can even connect to SSH before it dies, but the SSH session always dies. And the kindle restarts.