When an agile board is configured, by query, to display multiple active sprints, the Planning Board shows the sprints in an unknown order. They are not sorted by start or end date, number of stories, number of points or any other metric I could figure out. When a sprint ends and falls off of the board, the order of the remaining sprints sometimes changes - shouldn't they still sort the same relative to each other? IMHO, the sprint ending soonest should be at top going down to the sprint ending the furthest out. Providing a sort drop-down would be awesome.
This also causes the Sprint Health Gadget to display the wrong sprint when "Next Sprint Due" is selected as the sprint to display. That's why I marked it a Major priority.