So far, no reports on this thread, let's keep it that way!
You know, being born / raised in CA I had no clue what any of this meant until reading the whole first page of posts. Goes to show how amazingly different cultures there are even within the US and also in generations.
I would have never thought this would have been an issue or a topic of discussion. I brought it up to my wife (same age / also born and raised here) and she was just as perplexed. She mentioned that Oprah hates it when people call her Ma'am.
I've often used the title "ma'am" when talking to women customers, even when they are younger than me. Of course lately most of them are. I've never had anyone take offense to it although some said that they felt "ma'am" was what they mothers are supposed to be called.