[jQuery] just in Firefox 3.0.8 $ is not defined

[jQuery] just in Firefox 3.0.8 $ is not defined


Hi, i dont know what happen but just in FF, Jquery show error
error:
$ is not defined
my code:
<script type="text/javascript">
$(document).ready(function(){
     $('#demoOne').listnav();
});
</script>
yes, i have the url to the jquery and the plugin in nice place, but
idont know why just Firefox