Problema con Menú desplegable en Mozilla

[Benedetti1971]

Estoy haciendo una web, basada en joomla y con una tienda virtuemart, la tienda está en pruebas en http://shop.uno800.com/Joomla_1.0.13_eCommerce_Edition_VM_1.0.14 la cosa es que el menú desplegable de la izquierda (basado en el javascript JsCook) se ve correctamente en Explorer, pero en Mozilla los submenus salen por debajo del contenido web que queda a la derecha del menú...
me he repasado el CSS (todo y que no soy un master) y la verdad no consigo ver el problema que hace que se comporte de manera tan distinta en un navegador que en el otro...



el codigo embebido del javascript es este:

<script language="JavaScript" type="text/javascript" src="includes/js/JSCookMenu.js"></script>
<link rel="stylesheet" href="includes/js/ThemeOffice/theme.css" type="text/css" />
<script language="JavaScript" type="text/javascript" src="includes/js/ThemeOffice/theme.js"></script>
<div align="left" class="mainlevel" id="div_JSCook_menu_4858e75de57f2"></div>
<script type="text/javascript"><!--
var JSCook_menu_4858e75de57f2 =
[

['<img src="http://shop.uno800.com/Joomla_1.0.13_eCommerce_Edition_VM_1.0.14/components/com_virtuemart/js/ThemeXP/darrow.png">','TV, Video&Audio','http://shop.uno800.com/Joomla_1.0.13_eCommerce_Edition_VM_1.0.14/index.php?option=com_virtuemart&page=shop.browse&c ategory_id=1&Itemid=26',null,'TV, Video&Audio'
,
['<img src="http://shop.uno800.com/Joomla_1.0.13_eCommerce_Edition_VM_1.0.14/components/com_virtuemart/js/ThemeXP/darrow.png">','cat test 1','http://shop.uno800.com/Joomla_1.0.13_eCommerce_Edition_VM_1.0.14/index.php?option=com_virtuemart&page=shop.browse&c ategory_id=4&Itemid=26',null,'cat test 1'
]],
['<img src="http://shop.uno800.com/Joomla_1.0.13_eCommerce_Edition_VM_1.0.14/components/com_virtuemart/js/ThemeXP/darrow.png">','Mobile Phones','http://shop.uno800.com/Joomla_1.0.13_eCommerce_Edition_VM_1.0.14/index.php?option=com_virtuemart&page=shop.browse&c ategory_id=2&Itemid=26',null,'Mobile Phones'
],
['<img src="http://shop.uno800.com/Joomla_1.0.13_eCommerce_Edition_VM_1.0.14/components/com_virtuemart/js/ThemeXP/darrow.png">','Computers, Notebooks','http://shop.uno800.com/Joomla_1.0.13_eCommerce_Edition_VM_1.0.14/index.php?option=com_virtuemart&page=shop.browse&c ategory_id=3&Itemid=26',null,'Computers, Notebooks'
],
['<img src="http://shop.uno800.com/Joomla_1.0.13_eCommerce_Edition_VM_1.0.14/components/com_virtuemart/js/ThemeXP/darrow.png">','cat test 3','http://shop.uno800.com/Joomla_1.0.13_eCommerce_Edition_VM_1.0.14/index.php?option=com_virtuemart&page=shop.browse&c ategory_id=5&Itemid=26',null,'cat test 3'
],
['<img src="http://shop.uno800.com/Joomla_1.0.13_eCommerce_Edition_VM_1.0.14/components/com_virtuemart/js/ThemeXP/darrow.png">','cat test 2','http://shop.uno800.com/Joomla_1.0.13_eCommerce_Edition_VM_1.0.14/index.php?option=com_virtuemart&page=shop.browse&c ategory_id=6&Itemid=26',null,'cat test 2'
]];
cmDraw ('div_JSCook_menu_4858e75de57f2', JSCook_menu_4858e75de57f2, 'vbr', cmThemeOffice, 'ThemeOffice');
--></script>
<noscript>
<a title="TV, Video&amp;Audio" style="display:block;" class="mainlevel" href="http://shop.uno800.com/Joomla_1.0.13_eCommerce_Edition_VM_1.0.14/index.php?page=shop.browse&amp;category_id=1&amp;o ption=com_virtuemart&amp;Itemid=26" >TV, Video&amp;Audio</a>
<a title="Mobile Phones" style="display:block;" class="mainlevel" href="http://shop.uno800.com/Joomla_1.0.13_eCommerce_Edition_VM_1.0.14/index.php?page=shop.browse&amp;category_id=2&amp;o ption=com_virtuemart&amp;Itemid=26" >Mobile Phones</a>
<a title="Computers, Notebooks" style="display:block;" class="mainlevel" href="http://shop.uno800.com/Joomla_1.0.13_eCommerce_Edition_VM_1.0.14/index.php?page=shop.browse&amp;category_id=3&amp;o ption=com_virtuemart&amp;Itemid=26" >Computers, Notebooks</a>
<a title="cat test 3" style="display:block;" class="mainlevel" href="http://shop.uno800.com/Joomla_1.0.13_eCommerce_Edition_VM_1.0.14/index.php?page=shop.browse&amp;category_id=5&amp;o ption=com_virtuemart&amp;Itemid=26" >cat test 3</a>
<a title="cat test 2" style="display:block;" class="mainlevel" href="http://shop.uno800.com/Joomla_1.0.13_eCommerce_Edition_VM_1.0.14/index.php?page=shop.browse&amp;category_id=6&amp;o ption=com_virtuemart&amp;Itemid=26" >cat test 2</a>
</noscript>

Agradeceria muchisimo que alguien con más nivel que yo, me comente si ve alguna incongruencia en el codigo que pueda causar el problema, o que me diga si se le ocurre alguna solucion!

Gracias por anticipado.