In jQuery 1.8.3, change events generated by simulating a click event on a radio button appear not to bubble as they do if the click is generated by user action.

http://jsfiddle.net/smarcaurele/JMz53/

Notice that if you run this sample in IE8 you will not execute the change event handler unless you click on one of the radio buttons. In IE 9 or most all other browsers you will execute the change event handler when the page loads.

Also of note, is that if the sample is modified so that the change event handler is attached directly to the radio button instead of being delegated by the body element, then the handler will execute on page load for all browsers... even IE8.

This suggest that the change event is not being bubbled when it is generated by a call to click() and is being bubbled when is is generated by the user clicking the radio button in IE8 and lower.