Naughty Dog has indeed fix the demo, for everyone to enjoy
"Christophe Balestra, here, and I'm Co-President at Naughty Dog. I wanted to give a final update on the Uncharted: Drake's Fortune demo situation.
We're really sorry about what happened and didn't anticipate this at all. We just didn't know people from other territories could connect to the US PLAYSTATION Network Store and download demos … now we do! We've been too busy working on the game to wrap our head's around the infrastructure of the PSN"