When you make a lot of AJAX calls, the browser keeps all the requests in a queue and executes two at a time. So, if you click on something to try to navigate to anthoer page, the browser has to wait for running calls to complete before it can take another one. The bug is quite serious in IE 6 and unfortunately, it still exists in IE 7. Let's build a fake XHR object to solve the bug in Internet Explorer....