[jQuery] Simple list don't work in IE

Hi all,

I expect from the following code to display only the submenu of the
active menu. It works like a charm under Firefox and Opera but not
under IE (at least under version 7).
If someone could help, I would appreciate.

Here is the code:
$(document).ready(function()
{
  $("ul").hide();
  $("ul.level1").show();
  $("li.active").next("ul").show();
});

Here is the HTML:
<ul class="level1">
  <li>menu 1</li>
  <ul class="level2">
    <li>submenu 1 - 1</li>
    <li>submenu 1 - 2</li>
  </ul>
  <li class="active">menu2</li>
  <ul class="level2">
    <li>submenu 2 - 1</li>
    <li>submenu 2 - 2</li>
  </ul>
</ul>

Thanks in advance

---
Alexandre Lahure