JQuery :: Jumping Show / Hide In Chrome And Safari

I am building a simple show/hide list with the jquery. It works great on IE and Firefox but in Chrome and Safari the closing menuitems shift the whole menu to the left for a second and then back to its origin. I have about 20 menuitems that each hold about 5 submenu items. The goal is to show the 5 items only on mouseover on the menuitems and then hide it once the mouse moves away.

Here is the code:
<script type="text/javascript">
$(document).ready(function(){
//Hide all subsubmenus
$(".subcategories").css("display","none");
});
</script>
<li><a href="/kleinanzeige-aufgeben/geschenke.htm" onmouseover=" $
('.subcategories:not(#86)').hide('fast');$('#86').show('fast');"
title="Geschenke">Geschenke</a></li>