Activating DEVONthink.app in a Workspace fails initially

When activating DEVONthink the first time in a Workspace (that containes only one tabbed layout) the main DEVONthink window is not displayed. A second Workspace activation (DEVONthink running allready) often succeeds. Maybe a problem with startup times (some seconds depending on the database to load) and a splash screen that cannot be disabled.