JQuery :: Toggle Not Working On IE7 And IE6?

I´m trying to add some simple functions to a web page I recently created

This is the JQuery script:

$(document).ready(inicia);
function inicia(){
$("ul.sub").hide();
$("li.familias").click(mostrar);

[Code].....

Ok this are basically nested list that are created troguh php code. In essence it reads from adatabes and the it creates the list of items.Because the list is so large you noly see the families and when you click on the its suppossed to show the products on each list. It works on Firefox and IE 8. But IE& and IE7 it just stays hidden, nothing happpnes when I click.