I have a N800 with a defect headphone jack and the same problem.,..

Bought from Tiger Direct DOT CA and is a US item.

Nokia Canada won't do a thing for me, I inadvertently sent it to them thinking nothing of it...

The regional warranty thing is BS, cuz then Tiger Direct shouldn't be able to sell a US only item to Cdn customers. I don't recall anything in the item description about the warranty, but i am sure Tiger Direct.ca had it in the small print...
I was gonna post on here for all Cdn users to Buyer Beware!!

I emailed my situation to Nokia USA and will post their reply for what it's worth.