Tooltip disappears when changing inventory

This one is a bit difficult to describe, so I'll use a video: http://youtu.be/56MHncFdATA

Basically, when adding or removing items in the inventory, the tooltip for the next item that the mouse is now over won't be displayed until the mouse is moved. This makes it more tedious to quickly find out what each item in a set of subsequent related items (for example, armor) costs in a shop.

(RM-979 from redmine: created on 2013-11-30 by Vincent Beers, , closed on 2013-11-30 by scrawl .)