I too would like to know exactly what it is they're after with this "Give an example of a time you dealt with cultural diversity" question... stumped me a bit at the BA interview as I couldn't think of one off the top of my head. I'm a pretty open-minded individual, and as such have never had to "deal with" cultural diversity as such.
Any ideas?
FT
As you said, the best answer would be that you have never had to deal with cultural diversities, you accept every one is different and think it makes for an interesting world - or something random like that.