You’ve been warned. I have a lock code on my iPhone 3G, when i did the 3.0 update, it trashed the nvram so that there is no wifi hardware detected. Only solution is to go to Apple store and get a new phone. Took some digging, but here is an answer that makes sense
Apparently, Apple didn’t test this scenario, and there’s a bug in the upgrade process for those of us who’re security-conscious and use a lock code. The bug forces us to abort the upgrade process and start over; my guess is that this leaves the baseband nvram in a dorked-up state.
Folks who’ve yet to upgrade to 3.0 – my suggestion is to disable the
security code on your iPhone prior to performing the upgrade.