I've worked in a load of different countries , I love whistling , ( I hope it is quiet and melodic )and in Brazil I was asked not to do it in the office and in the lifts (elevators), whistling is associated with some bad / or something bad about to happen. They NEVER do it although they DO use whistles in a completely different manner to what we're discussing..
I'm in Norway at the moment - they just think I'm a normal, strange Brit.

Cheers

Betsy.