ev.originalEvent is undefined in slidechange

The following code worked in jQuery 1.3 with ui 1.7.2 but is broke in 1.4 with ui 1.8:

$(("div.slider").bind('slidechange', function(ev, ui) {
    console.log(ev); // prints event
    console.log(ev.originalEvent);   // prints undefined
    if (ev.originalEvent.type == "mouseup") { 
        // do something here
    }
});

Makes it difficult to check for mouseevents f.e. like is stated in the example with 'slidechange':

"Use event.orginalEvent to detect whether the value changed by mouse, keyboard, or programmatically."