I've got it too. What you could try with it, is taking Peter's pseudocode wrapper (earlier in this thread) and trying to recreate upgclient from sources.

If you can achieve that, then I can fix the serial port stuff to work better over USB/bluetooth style ports.

EDIT: or maybe I'll just enable kernel IP-autoconfig (CONFIG_IP_PNP, CONFIG_IP_PNP_DHCP) in Hijack, so that my ethernet upgrader.c can always work with any unit that has a Hijack kernel in flash. Some other tweaks would also be necessary, I suppose, to let ftpd run without a rootfs or /proc

Cheers