slow close times

Hey everyone.  I'm seeing some strange behavior, somewhat related to an old question of mine.

My app is maybe 4-5000 lines total, with a dozen control arrays, and maybe 100-150 controls.  So it's not gigantic, but it's fairly good sized.

Oddity: I'm seeing some very long application shutdown times.  That is, when I close the app with an exit button control, or from the app's Windows titlebar "X" icon, or from the menu, I can step through the process and I see several of the callbacks get called spuriously.  I believe that since these callbacks are getting called "one last time", it's probably adding up to the observed 13-14 seconds of shutdown time!

In the other post above, there was talk about including the "default: return 0;" case.  I like that and have included in all my major state machine timers.  Yet I'm still unable to shut down the app immediately.

Another observation: if I breakpoint right on the CloseCVIRTE line, I'm seeing a near zero time delay between clicking Close and this line.  It's after the CloseCVIRTE that the program hangs for 13 seconds.  And this portion isn't traceable.

My main loop skeleton:

int main (int argc, char *argv[])
{
	if (InitCVIRTE (0, argv, 0) == 0)
		return -1;  // out of memory error
	if (mainPanel < 0)
		return -1;  // out of memory error

	// display the GUI
	DisplayPanel(mainPanel);

	RunUserInterface();
	
	// close the GUI
	DiscardPanel(mainPanel);
	CloseCVIRTE();
	return 0;
}

Ideas?