mousehover + animation - hover the mouse fastly leads to two tabs remain open

i found the following bug when using jquery ui tabs ,

when i selected the event as mouse hover and added animation to it

$("#Tab").tabs({ "event":"mouseover",fx:{ opacity: 'toggle' , duration:'slow'}});

when i move the mouse over the tabs quickly , two tab contents remain open at the same time .

check this (mouse hover the tabs fastly , u can)

http://jsbin.com/iyubohttp://jsbin.com/iyubo

i think the problem is that Jquery UI Tabs is not using hover intent