Congratulations: that was the best mail I read in the last 2 months!!!!
Yesterday after quiting my job I added some explanations about this
behaviour in X (MDI contra SDI):
http://www.esh.uni-linz.ac.at/~mother/hci/menus/file.html
(please RELOAD).

You understand what you are talking about and your mentioned behaviour
in the menus: great!

Peter

PS: I'll make some changes in the behaviour (New...) like suggested by
you before really quitting my job.