[NiLuJe]

Put the linkjail folder from the latest packages back on the root of your kindle, reboot your kindle, then try to ununinstall/install the latest jailbreak again.

FYI, your SSH settings have nothing to do with the usbnet hack install/uninstall process, in fact, uninstalling it won't touch them. Also, the whole point of the shared keys auth method is that you don't depend on a password set on the server side, but on the one you set for your private key, so I'm a bit puzzled...