Hmm, it should have been doing it with any older WACUP builds as that's what the winamp skins tend to do unless a skin has been specifically coded not to that behaviour (which is only possible if it's a winamp3 / modern style & in the current builds isn't possible to disable for classic / 2.x style skins).
If it's a classic / 2.x style skin then there's an option which is already present for the next preview build, for the other skin types then there's no simple toggle option to do it.
-dro