While editing a Slide object and you remove a SlideState, the "Remove State" confirmation dialog box that appears is not modal -- it appears in its own taskbar icon.
This can result in the dialog appearing behind the application. This also can result in deleting a SlideState and then unknowingly having multiple dialogues present in the background of the application.
Update to E-Prime 18.104.22.168 or later.
This item in E-Prime 22.214.171.124.