When you click on an event title you see a word duplicated but when you edit the event description the word is not duplicated.
This is a known bug in Microsoft Internet Explorer browser which, very rarely, causes a word to be duplicated in the event description popup window. You can verifty this but by clicking on the side of the popup window and widening the window. The duplicate word magically dissappears! This problem does not exist in other browsers such as Firefox.
The only work around at this time is to add some additional text or line breaks to the description which may create a condition where this bug does not occur.