Megamenu drop down hanging (not auto-collapsing) in IE7,8 and Safari

On IE7, IE8, and Safari (can't seem to duplicate problem on FF), the drop down menus (megamenu) will not collapse if you move your mouseover the menus quickly. It will work if you roll on and off, but if your cursor quickly goes over the menu link, and onto another part of the page, the drop down will just stay open and not close.

I have not yet upgraded Corporate2 with the latest patch, is this something that is fixed in that?