Mouseover problem

When I make a mouseover I make a tween from the normal
button state to the mouseover state and a mouseout tween
from the mouseover state to the mouseout state…

The problem is that when someone is moving his cursor
fast over the button the tweening to the mouseover state
hasn’t finished yet when he starts the mouseout tween and
that doesn’t always look smooth enough.

What is best the way to solve this?

thanks