The Backlog button in the left hand pane was gone. Then came back, then gone again. No changes to issues with the "Planning" status were made during this problem. (See comments below for detailed repro)
URL to kanban backlog view redirects to kanban board when Backlog button is gone from left hand pane.
(/secure/RapidBoard.jspa?rapidView=2&projectKey=XXX&view=planning.nodetail)
