To Tabletrat and Geneven: I stand corrected. I agree, in general, GPS should work under most altitude, mine is not, dont know why. And as other people has put it, theirs work in USA/Europe/Asia. Mine does not work in Asia at all. But now I am back in USA, the BT GPS works like a charm. Does GPS has to log with a 'particular' satellite, or any satellite, with tirlaterization will do? witch crafts! bun