People are often used to seeing things made in Director or Flash where buttons will change states (move etc.) and/or play audio as a "rollover".

DVD SP (not due to a DVD SP, but DVD SP specs) does not make rollovers - for instance there is no way to assign a sound to be played when a button is selected.

There are some workarounds to try, both within DVD SP and also using other apps, but none of them will be as smooth as most people want or envision. For instance, layered menus will give the appearence of a rollover, but it will not be consistent across all players.