When I select certain sub pages from the site map or side nav, instead of editing the page I selected, the wiki creates a brand new page (not a sub page) with a simialar name which results in duplicates.

 

What I THINK is the problem is this: I happened to copy a "tab" character into the page name when creating the original page. The pages that did not have the accidental tab cut/pasted into the page name behave normally.

 

Then it is impossible to delete the tabbed-named page because I cannot access it.