Button in upper left corner

Question.  I am using Atlantis word processor.  Every time I open it, a button shows up in the upper left corner and stays there until I minimize or close the application.  I have spoken to Atlantis about it and they say it must be something in Windowblinds causing it.  Is there anything that can be done about this or it is normal?  I am running the latest version of Windowblinds, Win8.1, (it has also happened with past versions) and only with Windowsblinds running.

Thanks.