that's working very well !
i've too configured before g:/kindle/usbnetwork/info with the good IP
under vista, the driver "RNDIS / Ethernet Gadget" is not found
but under ubuntu, you've just to configure /etc/network/interfaces
with (my lan is 71, it is usually 1) :
iface usb0 inet static
ifdown usb0 (usefull sometimes)
hope that helps !