To add to Mike's work around...
If you have access to your moodle database via phpmyadmin, find the table titled 'mdl_wiki'.
Browse that table and edit the entry for the wiki you want to change, then change the entry for 'firstpagetitle' to whatever you want your front page to be called. Save the change and make a mental note of the page contents and the previous first page title.
Find the table 'mdl_wiki_pages'. Browse that table looking for the previous page title in the 'title' field (if you just made the wiki, it will be the last entry)and the page contents in the 'cachedcontent' field. Edit and change the title to be the same as you changed it in 'mdl_wiki.' Save your change.
That's it...no need to copy contents and no need to delete an orphaned page, just go refresh/reload the browser view of the wiki and it should have the content on the newly named page.
"Not ideal I know, but it does work..."