As it goes, I have tried mms:// and that works on the 900 (but it hangs my Totem Linux player for some reason).

Why could I save URL's as mmsh before and not now?

Edit - will there be less data transfer with mms than mmsh in that case? Is that what I have been doing wrong?

Edit 2 - for some reason my Totem player has now decided it likes mms, my head hurts