. I have long since given up the notion that Americans don't 'do' irony.

A nice reminder of the dangers of generalising, thanks. I'm sure you will acknowledge certain "national traits" in humour, though. For example, from what little I know of the subject, it seems that most American males find "The Three Stooges" hilarious - an unfunnier bunch I could scarcely imagine. Now that's cruel humour!