For anyone still reading...

... I have confirmed there is some kind of serious issue with the "new" N900; it cannot charge a battery fully over any period of time, and will discharge a battery (that has been charged externally) within 90 minutes even while switched off.

So... it's stuffed.

I have gone through a lengthy process with the provider, finally got bumped high enough up the ladder to get to someone who said, "right, so, we need to get you a new handset."

So I have a new Galaxy S2 coming next week, no charge.

They don't want the N900 back.