No racism intended, but black people seem to have a less pleasant odor than whites. I notice east-indian people smell funny as well, but they have a very odorous diet(curries, tandoori, etc) and it comes through their skin. Blacks eat the same food as white people, so I'm not sure what their excuse is other than terrible hygeine.
Anecdotedly, I've heard stories of blacks being more prone to diseases that cause them to smell horrible.