To reproduce this problem edit a page with the WYSIWYG editor, enter some text with an accent that corresponds to a non existing page, for instance "Accentué", select the text and click on the link tool, accept defaults by clicking on the "Insert" button. Click on the "Save & View" button. Click on the link to your new page to create it, save your new page. When you go back to the parent page and reload you will notice that the question mark indicating the new page does not exist will still be displayed.
It seems the URL for the editor when you click on the link to create the new page contains "Accentu%E9". This also creates problems with the What's New page where the newly created page show up with a question mark icon next to it and also the Navigation widget which has similar problems.