jqueryui tabs prevent from bubbling up

Question

Does anybody know why this works

  $('#tourDetailsTabs').tabs({ fx: { opacity: 'toggle'} })
 .bind("tabsselect", function (event, ui) {
  event.stopPropagation();    //http://dev.jqueryui.com/ticket/4110
 }).bind("tabsshow", function(event,ui){event.stopPropagation();});

while that doesnt?

$('#tourDetailsTabs').tabs(
{
    show: function (event, ui) { event.stopPropagation(); },
    select: function (event, ui) { event.stopPropagation(); },
    fx: { opacity: 'toggle' }
})

Actually the second looks much nicer but it doesn't prevent the tabs from bubbling while the first one does...