UPDATE: It's my old adapter's fault, not the N80i's fault. I don't think my 8 year old ACP-7U works with modern N series phones. I switched to a new North American N Series adapter that Andy sent me (thanks! got it December 27th) courtesy of the Bloggers Relations program and all is well.
For some reason, my old Nokia adapter with the plug converter doesn't work with the N80i (error message is "Not charging"). This is very strange since it works with the N93. I would assume that the N93 being bigger and having a bigger screen would require more power so it can't be that my old Nokia AC adapter doesn't give enough power. I guess I'll have to buy another Europe->Canada/USA converter tomorrow and change the SIM back to the N93 since the battery is dead.