There is a good chance there is another "ghost" document lying around in the database you can't see. I'd suggest you go in the Recycle bin look for it and delete or remove it. You might also run the VIEW query to find it. Run this and put a where clause on it filtering out by your pages name:
SELECT *
FROM View_CMS_Tree_Joined
WHERE DocumentName like '%Part of your name%'
This should give you the document in question. Last resort would be to manually modify the record in the database tables or manually remove it from the database tables.