I tried to upgrade an IP 406 last night to 3.1(29) and the upgrade failed; had to go on-site and use the DTE port. I don't know if it was just bad luck, but even after erasing the config it wouldn't boot with the ip406.bin included with the CD download. So, anyone who hasn't tried this, you might want to be extra cautious -- it made for an annoyingly long night of work last night for me.