jQuery nav not responding

I'm building a navigation that is built heavily on jQuery. I have it working as needed except that when mousing over links to quickly it spikes the processor and the navigation hangs. By hangs i mean it stops working and even the links will not show rollover states. I thought it was just a matter of adding a stop() but this changed nothing. Any ideas?

Here it is online http://sb.cesarvillaca.com/nav/nav.html

The code is below.

			
<div id="ProductsNav-ov" style="display:none;"></div>

<div id="main-nav">

<ul>
	<li class="mainnav-click" id="ProductsNav">PRODUCTS</li>
</ul>

<script type="text/javascript">
<!--
$(function() {

	$('.mainnav-click').mouseenter(function() { 
		//alert($(this).attr('id'));
		buildNav($(this).attr('id'));
	});

});

function buildNav(nav,sub){

	//alert(nav);

	var Shredders = new Array({
		Deskside: '',
		Professional: '',
		Commercial: '',
		Government_Approved: '',
		Supplies: ''
	});

	var Records_Storage = new Array({
		Storage_Drawers: '', 
		Storage_Boxes: '',
		Earth_Series: '',
		Classroom_Organization: '',
		Moving_Boxes: '',
		Magazine_Holders: '',
		Sorters: ''
	});

	var Workspace_Ergonomics = new Array({
		Keyboard_Trays_and_Drawers: '', 
		Palm_and_Wrist_Supports: '',
		Monitor_Supports: '',
		Back_Supports: '',
		Foot_Supports: '',
		Copyholders: '',
		Monitor_Filters: '',
		Machine_Stands: ''
	});

	var Workspace_Organization = new Array({
		Desk_Organizers: '', 
		Cubicle_Organizers: '',
		Literature_Organizers: '',
		Mail_Carts: ''
	});

	var Computer_Accessories = new Array({
		Keyboards_and_Mice: '', 
		Mouse_Pads: '',
		Cleaning_Supplies: '',
		Power_Protection: '',
		Keyguards: ''
	});

	var CD_DVD_Products = new Array({
		Jewel_Cases_and_Inserts: '', 
		Desktop: ''
	});

	var Binding_Machines = new Array({
		Plastic_Comb: '', 
		Wire: '',
		Thermal: '',
		Supplies: ''
	});

	var Laminating_Machines = new Array({
		Personal: '', 
		General_Office: '',
		Supplies: ''
	});

	var Cutters_and_Trimmers  = new Array({
		Cutters: '',
		Rotary_Trimmers: '',
		Supplies: ''
	});

	var Mobile_Accessories  = new Array({
		Mobile_Accessories: ''
	});

	var Refurbished_Shredders  = new Array({
		Refurbished_Shredders: ''
	});

	var Where_To_Buy  = new Array({
		Where_To_Buy: ''
	});

	var ProductsNav = {
		"Shredders": Shredders, 
		"Records_Storage": Records_Storage, 
		"Workspace_Ergonomics": Workspace_Ergonomics, 
		"Workspace_Organization": Workspace_Organization, 
		"Computer_Accessories": Computer_Accessories, 
		"CD_DVD_Products": CD_DVD_Products, 
		"Binding_Machines": Binding_Machines, 
		"Laminating_Machines": Laminating_Machines, 
		"Cutters_and_Trimmers": Cutters_and_Trimmers, 
		"Mobile_Accessories": Mobile_Accessories, 
		"Refurbished_Shredders": Refurbished_Shredders, 
		"Where_To_Buy": Where_To_Buy 
	};
	
	if (sub==undefined) {
	
		var navPOP='';
		navPOP+=

		'<div id="drop-down-container">'+
			'<div id="mainnav-title-ov">'+
				'<div class="sprite main-nav-left lfloat"></div>'+
				'<div class="main-nav-center auto-width">PRODUCTS</div>'+
				'<div class="sprite main-nav-right lfloat"></div>'+
				'<br class="clear">'+
			'</div>'+
			'<div id="drop-down" class="auto-width">'+
				'<div id="mainnav-container" class="dots">'+
					'<ul id="mainnav">';

					var navname = "";
					$.each(eval(nav), function(mainNav, mainNavobject) {

						$.each(mainNavobject, function(i, subNavobject) {

							$.each(subNavobject, function(property, value) {

								if (navname != mainNav) {

									navname = mainNav;
																							
									navPOP+= '<li><a href="' + value + '" class="subnav-click" id="' + mainNav + '">'+str_replace("_"," ",mainNav)+'</a></li>';
								
								}

							});

						});

					});

					navPOP+= 

					'</ul>'+
				'</div>'+
				'<div id="drop-down-sub"></div>'+
				'<br class="clear">'+
			'</div>'+
		'</div>';

		var whatmenu = nav+'-ov';

		$('#'+whatmenu).html(navPOP);
		$('#mainnav-container').removeClass('dots');

		$('#'+whatmenu).position({ my: "left top", at: "left top"});

		$('#'+whatmenu).show();

	}else{
		
		//$("#drop-down-sub").stop();

		$('#drop-down-sub').empty();

		var navPOPsub='';
		navPOPsub+= '<ul id="subnav">';

		$.each(eval(nav), function(mainNav, subNavobject) {

			$.each(subNavobject, function(property, value) {

				navPOPsub+= '<li><a href="' + value + '">'+str_replace("_"," ",property)+'</a></li>';

			});

		});

		navPOPsub+= '</ul>';

		$('#mainnav-container').addClass('dots');
		$('#drop-down-sub').html(navPOPsub);
		$('#drop-down-sub').show();
	}

	$('.subnav-click').mouseover(function() { 
		buildNav($(this).attr('id'),1);
	});

	$('#drop-down-container').mouseleave(function() { 
		$('#ProductsNav-ov').hide();
	});

}
//-->
</script>

</div>

</div>

Code (markup):