Summary:
action.admin_editevent.php not incrementing of $item_id when inserting
Detailed Description:
When action.admin_editevent.php gets called and $event is not set, a new event
is being inserted. But the item_id column of this new event is not being
updated, so dublicate event_ids are being created.
Additionaly there is no unique column specified in the table, so this error
isn't being caught by the mysql server.