Widgets "shifting" content

I noticed an odd behavior with the widgets. When certain “events” happen, the content of a widget will get shifted upward to the above widget. The top widget then loses it’s content as there is no other widget for its content to move into.

These “events” include changing the # of footer widgets. When I changed the # of footer widgets from 3 to 4, the above behavior happened and all widget content shifted under the title of the widget above it in the admin panel.

Another “event” causing this behavior was adding the suggested plugin bbPress. This plugin added its own widget. When it did, all of my widgets’ contents shifted again.

Bug?