Logos Bible Software 4.3 SR-5 (4.30.0.1603) Running on a Windows XP system with latest updates.
Scenario: While viewing a user customized Logos window, select "Home" icon in upper left to get the Home page. Next select the "?" icon in the upper right corner and click on "About Logos Bible Software".
The "about" window will appear, then the underlying Home window will switch back to the layout it was at before the home screen was invoked and the "About" window will switch to the background as an "unselected" window so it is now behind the main window, thus it seemingly disappears. Closing the "about" window does not reinstate the "home" page.