Just about everybody. It's a bug between the Sony Transfer Tool program and how it communicates with FCP. It was supposed to be fixed in the latest Sony Transfer Tool update but no joy. Delete all your dupes in the browser window and then use the "Import Files" command within FCP to go to the actual folder where the EX clips reside and import them again. This time there will be no duplicate names.
Another way to avoid duplicate names is to use The Sony Transfer Tool as a stand alone app. Transfer the files from your card to your media drive with the program, then start FCP and choose "Import FIles".