Well, here's my scenario:
I have an extension (toolbar created in VB6) to an application.  I want
to include some .NET controls in the extension (ie. the user clicks on
a button on the toolbar and the extension calls a .NET class which
opens a .NET form with .NET controls).  This class also handles events
that are raised from the application (I pass a reference to the
application from the VB6 extension to the .NET class).  Now, when the
user closes the .NET form, I want all references to the application to
be cleared so that the event doesn't fire in the .NET class anymore.

However, in my situation the event is still firing from the .NET class
even after directly calling the Dispose method (below) from VB6.
(Although I no longer get the StackOverflowException).

~clsWindow()
{
Dispose(false);
}

// Implement IDisposable.
// Do not make this method virtual.
// A derived class should not be able to override this method.
public void Dispose()
{
Dispose(true);
// Take yourself off the Finalization queue
// to prevent finalization code for this object
// from executing a second time.
GC.SuppressFinalize(this);
}

protected virtual void Dispose(bool disposing)
{
// Check to see if Dispose has already been called.
if(!this.disposed)
{
// If disposing equals true, dispose all managed
// and unmanaged resources.
if(disposing)
{
// this object is a .NET form called by the .NET class
m_objNETWindow.Dispose();
}
// These objects were passed in from the VB6 application
Marshal.ReleaseComObject(m_pAVEvents);
Marshal.ReleaseComObject(m_pMxDoc);
Marshal.ReleaseComObject(m_pMap);
}
            disposed = true;        
        }