When autocreating a page (after clicking on a red link) the wiki defaults back to the default area and simply adds the prefix (if any) to the page title. While this can be avoided by an observant user correcting it in the wiki edit page, it should really default to same area and prefix as the red link.

Furthermore, after making that mistake, deleting the page results in the link still leading to the deleted page (a page to which the admin gets a "no permission" error.

It is not possible to recreate a new page with the same name after deleting it.