If an event handler is attached and later detached from an element, the jQuery.event.global[type][index] element will be undefined as it was delete-ed out of the array. The IE cleanup code needs to check for that and skip the call to remove the event. Otherwise it crashes on the element.$events reference in jQuery.event.remove since element is undefined.

This fixed the problem for me.

http://dev.jquery.com/browser/trunk/jquery/src/event/event.js#L994

< jQuery.event.remove(els[i-1], type);
> els[i-1] && jQuery.event.remove(els[i-1], type);

Sorry I don't have a simple test case, I found this while resurrecting work on the splitter.