We are using Dynamics CRM 2011. In some cases, clicking Queue Item Details displays the message "This record is in multiple queues. Go to the specific queue to view the details".
I'm required to clean up the existing duplicates queue items using Advanced Find manually. The issue appears to be specifically related to reactivation of resolved case, in which resolving the case updates the original queue item status to Inactive, then re-activating the same case creates the new queue item with status as Active and keeping the old queue item with status in active.
There are workflows associated with a case, which creates queue item on create/update of case.