Tween menu problem

programming flash
1

Hi
I have what should be a simple help menu that smoothly bounces in on a rollover and on rollout retracts to its origional place. The code works but if you rollover and rollout fast the rollout is detected before the rollover has completed and the menu disappears.

I have tried messing about with onMotionFinished but this made the situation more erratic.

Here is my basic code

import mx.transitions.Tween;
import mx.transitions.easing.*;
help_mc.onRollOver = function() {
var myTween:Tween = new Tween(help_mc, “_y”, Bounce.easeOut, help_mc._y, help_mc._y+150, 1.5, true);
};
help_mc.onRollOut = function() {
var myTween:Tween = new Tween(help_mc, “_y”, Bounce.easeOut, help_mc._y, help_mc._y-150, 1.5, true);
};