When a case is being cancelled and it does get reactivated, e.g. by an email sent from the customer, the case gets reactivated, however the queue item doesn’t. So the agent may see the case in one of his cases list views, but it won’t show up anymore in any of the queues. There is a workaround that has been suggested, just still I am wondering if such behavior is really wanted by design. From my point of view, upon reactivation of a case, the queue items should get reactivated as well.