aria-live and JAWS

I'm trying to get an aria-live region to work correctly with JAWS 11 and IE8.

Using the code below, I can get JAWS to announce the new value when the button is clicked, but the behaviour is not what I would expect.

JSFiddle of this example

<!DOCTYPE html>
<html>
<head></head>
<body>
    <button onclick="document.getElementById('statusbar').innerHTML = parseInt(document.getElementById('statusbar').innerHTML) + 1">Update</button>
    <div id="statusbar" aria-live="polite">0</div>
</body>
</html>

Using my JAWS11/IE8 configuration, on each click of the button I hear:

Click number  HTML Value (after click)  JAWS says
------------  ------------------------- ---------
1             1                         "Update button 0"
2             2                         "1"
3             3                         "2"

The problem, and my question is: how do I make JAWS announce current value of the aria-live region, rather than the previous value of the aria-live region?

I'd also be interested in how other screen readers will handle this functionality.