If you open the notifications panel, then click to edit an app, then close the popup window, then the panel window will stop redrawing (until you click "<" to return to the main control center view). (Usually... sometimes it doesn't happen until the second time I do it.)

By "stop redrawing" I mean that the window continues to respond to events, but nothing changes appearance. So, eg, you can roll the scroll wheel over the list, and the list doesn't move, and you don't get hover effects, but then if you click, it will show you the settings for the app that "should" be under the pointer (given the fact that you scrolled), not the app that's actually visible under the pointer (which hasn't changed).

(And it's not just the list that's affected; you don't get hover effects on the titlebar buttons either.)