[jQuery] Animate Delay Issue

[Wolf]

I have a strange delay issue.

I'm working on a menu animation.  When a user moves their mouse to the
top, it will move the menu up and when they move their mouse to the
bottom, it moves it down.  When I first move the mouse over the menu,
the animation fires.  But there is a big delay (maybe 2 seconds)
before it will fire again, after I move my mouse back on it.

However, if I change the animation speed from 2000 milliseconds to 10
milliseconds, it will fire right away.

Any Suggestions? Thx.

Here is a simplified version of my code:
$("#menu").mousemove(function(e){
        if (e.pageY < 100) {
                $(this).animate({
                        top: "-200px"
                }, 2000 );
        }
        if (e.pageY > 300) {
                $(this).animate({
                        top: "0px"
                }, 2000 );
        }
});