Queue tables by default have some underlying attached to them.
Oracle documents them as
AQ$_"queue_table"_I (the dequeue IOT)
AQ$_"queue_table"_T (the time-management IOT)
AQ$_"queue_table"_S (the subscriber table)
AQ$_"queue_table"_H (the history IOT)
After an upgrade we noticed that the queues just would not function until they were dropped and recreated.
This seemed a little ruthless so we then exported the queue tables along with these IOTS.
Then dropped the queues and tables in the upgraded system and imported them.
Easy fix :)