Button transitions in DVD SP doesn't point towards animation in the appearance of the buttons but rather they are animations that happen after the user activates a button and before the button's destination.
H
Half of what you need (delaying the buttons' appearance) can be achieved by setting a loop point in DVD SP. The loop point allows you to set the specifc time spot in which buttons become visible (and it's also the place from where subsequent repetitions of the menu cycle happen and that's why is called loop point). If you really need animation in the buttons' appearance, then you want first to make sure you understand how highlight maps are imported and assigned, and also you're looking at designing your menu background in a motion graphics application (Motion, After Effects or even Livetype). An editing application like FCP is not ideal, but may be good enough for simple cases.
Hope this helps.
Adolfo Rozenfeld
Buenos Aires - Argentina
www.adolforozenfeld.com