[jQuery] $.ajaxSetup and timeout

[jQuery] $.ajaxSetup and timeout

Hello,
I want to load some html content that changes over time, so I need to poll the server for changes from time to time. Could anyone point me to an example of how to do this? The documentation I found contains no example... I tried the following:
$.ajaxSetup( {
   timeout: 5000
 } );
$(document).ready( function() {
    $("#podcast_items").load("podcast_items_updater.php");
});
But the load does not fire again after those 5 seconds. I also tried including the ajaxSetup in the ready() block, and I also tried the deprecated (according to the manual) ajaxTimeout, but none of these seem to work.
Thank you!
Emi Polak