Guess Ive got pie on my face then......didn't realise you were quoting my post.
I think the crux of the problem is that Australians have a more refined sense of humour than the average American and one other thing I've noticed is that Americans don't know how to laugh at themselves. Making a joke about America in the presence of Americans can land you in a whole heap of trouble. An American making jokes about Australians amongst a bunch of Australians has little to fear...apart from eventually having his joke backfire badly on him/her.