Could someone please explain why this code work inside VFP and not from a EXE?

This code is from the File|Exit menu to close all open forms before quitting the application. For a reason I can't catch, it will loop indefinitly, refusing to release the form. There's no message and the Release() method is called (I placed a WAIT WINDOW inside the IF to check it).

I'm using VFP 5.0

llExitOK = .T.

DO WHILE llExitOK AND (Type("_Screen.ActiveForm") = "O")
	WITH _Screen.ActiveForm
		IF .QueryUnload()
			.Release()
		ELSE
			llExitOK = .F.
		ENDIF
	ENDWITH
ENDDO

TIA