Ajax request inside update panel...synchronous?

Question

Hi, please bear with me, hope you can help me out:

1. I have 4 .NET LinkButtons and a .NET Placeholder inside a .NET UpdatePanel.
2. When i click one of the aforementioned LinkButton, a user control is loaded in the PlaceHolder;
3. All LinkButton are set as AssyncPostBackTriggers of the UpdatePanel;
4. It's all good so far...everything works out fine...until...
5. One of the loaded user controls fires a javascript function that makes an ajax request to another script (via jQuery's ajax() function);
6. This works fine too, except that clicking one of the four LinkButtons does not work (read: it's Click event is not fired) until the ajax request doesn't end!!!;
7. Calling abort() on the ajax request doesn't work either, the LinkButtons event seems to be hanging there waiting for the request to finish.

Is this "expected behavior" or am i missing something here?
I know i shouldn't be messing with .NET Ajax and "normal" AJAX but this is kind of a requirement for the work I'm on now and i don't have a say in that.

Hope you can help me out, thanks in advance!

EDIT (added ajax code):

$.ajax({
type: "GET",
url: "proxy.aspx",
data: "op=getstatus&id=" + "1",
cache: false,
error: function (msg) {},
success: function (msg) {}
});