The fun never ends. We stopped at a local Brussels Nokia service point. They tried upgrading my software but ran into some weird problems ("we couldn't load one of the files" -- huh?). So, they've still got my phone and will hopefully get it all sorted out. There may or may not additionally be some kind of hardware fault.
If the conclusion is that they need to send the phone to Nokia, there's a ten-day turn-around time on that, meaning I would have to ask one of my friends here to pick up the phone and ship it back to me in the U.S.
*sigh*