See this Comm Center thread. The fundamental problem is: If an instance of Planner is started by inserting a target from within Starry Night, that instance has references from SN. If the user closes the window, he thinks the Planner instance has exited. It has not. Then the user starts a second instance. Now things are confused.



Two things are needed:


    
Add code that will prevent multiple instances, and if a second copy is attempted, force the window of the running copy to appear.
    
If a call is mace from a COM client into Planner, and it's main window has been closed, force it to (re)appear.