Thought to properly close this ...

I sent back the faulty unit through UPS. Never got any receipt acknowledgment from them after UPS's delivery confirmation for 2 weeks. Phone calls and e-mails many times, and they never went anywhere.

At the time I was about to give it all up, there comes a US post service parcel with a replacement unit from Nokia with a note saying the original unit could not be repaired.

Anyhow, the end of story.

Oh, there are two hot pixels on the new unit, well ...