[jQuery] jquery code works with firefox but not ie.

I have the following code that works in firefox and google chrome
using jquery 1.2.6.

function setUpClient()
{
$.post("http://localhost/gestivov2/include/ajax/getclients.php", {},
function(data){
$('#left_items').empty();
//alert(data);
$("client",data).each(function(id) {
client = $("client",data).get(id);
$("#left_items").append("<li id='"+$("id",client).text()+"'><a
href='#'>"+$("name",client).text()+"</a></li>");
});
})
}

It doesn't work with internet explorer 7, 8 beta nor 6. If I uncomment
the alert code, the xml data gets displayed so it looks like the code
within the each block is not being executed. What am i doing wrong?