jQuery Ajax Call to JSON not working in IE.

jQuery Ajax Call to JSON not working in IE.

I've got this code, I'm doing a ajax jquery call to json... It works in
everything but IE.
jQuery.ajax({
url: "/session/json.php",
type: "GET",
data: "",
success: function(data) {
I did some googling and I changed it to
jQuery.ajax({
url: "/session/json.php",
dataType: "json",
cache: false,
contentType: "application/json",
type: "GET",
data: "",
success: function(data) {
And Yay, it worked in IE.
However making that change broke it in all the other browsers.
I then tried:
if (jQuery.browser.msie) {
Do the bottom one, else { do the top one.
This also did not work, it seemed to work in all browsers apart from IE
again.
Has anyone else come across this error? any ideas how to fix it?
Thanks heaps.