The new Quick Links menu doesn't display correctly on some of the search results pages such as New Posts, Unread Posts and so on.
The problem is caused by the z-index set in the stylesheet for the dropdown menu (it's a div with class "dropdown hidden"). The z-index is set to 2 but needs to be at least 31 in order to avoid beng displayed behind some of the elements near the top of the page. For example, on Unread Posts there is a div with class "action-bar top" which has a z-index of 30 and therefore appears in front of the Quick Links menu.
Hope this helps.
マイケル