You cannot remote-upgrade an IPO!!
It's only when your upgrading from 2.1 it's possible.
Your remote 406 have now erased it's *.bin file, and is broadcasting a TFTP-request on the local network.
You need to.
1. Set up a PC with a TFTP-server (Manager)
2. Change the PC's IP to the 192.168.42.0 range
3. Look in the Manager's TFTP-log, where you should see the request
4. Write down the IPO's IP-adr. and mac-adr.
5. Create a Bootp-entry with the details, pointing to the ip406.bin file (just use v2.1)
6. Boot the IPO (shouldn't be neccesary)
7. The unit should now come up with a green light!
Hope this helps!