Can anyone point me in the right direction with this?

Can anyone point me in the right direction with this?

I have an interactive menu on my potfolio page  http://nesteggdesigns.co.uk/portfolio/main.html, it is split up in to different boxes which, when hovered over, display a slider over the top of each relevant box, this slider div contains info etc.

The problem that i am having is every time the box is hovered over the animation seems to slow down each time and also I need to be able to only use the amination when the mouse is on it for a longer period of time, or it gets stuck and just goes backwards and forwards its really irritating. Please help me it would be appreciated so much!!

here is a copy of one of the boxes


<div class="nav fadeout lbox b">
<img class="portfolio_images img2" src="images/display2.png" width="280px" alt="mac computer                  web design hull" class="navimg img1">
                  <div class="boxbslider sliders">
                  <img src="" alt="" class="logo">
                  <p class="slidertext">lorem ipsum dolor sit amet, consectetur </p>
            </div>
</div>

and one of the jquery functions



(function(){

var divb = $('div.b'),
boxb = $('div.boxbslider'),
slider = {

init:function(){

   divb.on('mouseover', function(){
boxb.animate({'top' :'0px'}, 300)

divb.on('mouseleave', function(){
boxb.animate({'top':'-200px'}, 300);
});



});

}
};
slider.init();
}());


thankyou so much you dont even understand how much you can help me here xx