I don't know why but it really annoys me when people who are not familar with someone call them something other than what that person goes by.
For example, let's say I'm talking to a friend named Angela and another friend of MINE comes up. I introduce them and later my friend calls my other friend Angie. That grates me.
I guess because I think it's respectful to call them by what they choose to be called not what you choose to call them. How do you feel about this? Does it matter to you? How about if someone does it TO YOU?