updating ruin unlock?

I recently purchased an unlocked HTC Aria. Since I do not have the unlock code myself, if the phone were to lock again i'd be SOL. I intend to update the phone to android 2.2, and am concerned that the phone will relock once updated.

The phone is the Asian model and is running software similar to the North American with some slight differences. Will it be possible for for me to update to the North American Froyo and make things more 'American' for myself?

has anyone had an experience updating an unlocked phone's firmware? what was the result?

 

thanks for the move.
I wrote HTC and here is the response for anyone who has the same concern:

"I understand that you would prefer to have the "American" software for your Aria. The only software that is an American version at all is for the AT&T version, and as it is carrier-branded firmware and not intended for your Asian Aria we could not condone putting it onto your device, even if it would go on there. It could cause serious problems on the device; it was simply not meant for that version of the phone. It could also prevent any future updating, and as there is not a North American 2.2 (which, again, would be AT&T software and probably not very useful for your version of the Aria). All things considered, it is best to stick with only the firmware designed for your version of the device. I do apologize for any inconvenience you may have experienced."