Thank you frankz - you seem to have cracked this for me! It's early days yet, but so far things seem to be behaving in the way I was looking for.
The key was pointing me in the direction of "display using this view" - in all the material I'd read about playlist sorting, no-one had mentioned that this is where you can permanently (hopefully!) determine the sorting of the playlist. Of course in retrospect it might appear obvious, but believe me it wasn't until your post. So many thanks for that
> However, if you like the way iTunes does it better, that software is still available.
Slightly below the belt, that one... There's no way I'm going back to iTunes, for reasons I'm sure everyone reading this will understand. But that doesn't mean we can't try and improve MB - or at least make its inner secrets more widely known. There's no need to LOL - I love MB because of the level of customisation available, but you have to admit that sometimes leads to a profusion of options and routes through them.
Thanks again all, particularly frankz and Freddy Barker. I'll let you know if I have any nasty surprises, but I think the query has been answered...
Simon