I didn't see any READ EVENTS (unless you comment it just before the posting)
I shoud do this that way (not saing that is the righ way :o)))

public m.ctrl
m.ctrl=0

SET PATH TO c:\comware && Better If You have relational PATH instead of this. something like SET PATH TO comware or \comware

** I suppose You have DEFAULT DATA SESSION In all Your forms
set century on
set safe off
Set hour to 24
set exclusive off
SET MULTILOCKS ON
set sysmenu off
SET REPROCESS TO AUTOMATIC
Open database helpdesk share
Do inicilo
if m.ctrl # 1
  do form frm_barrappal.scx && In that form in Destroy event You need CLEAR EVENTS command
  read events
endif
WAIT WINDOW "Hasta una próxima ocasión." noWAIT
Close data all

Procedure inicilo
WITH _Screen
    .BackColor=rgb(192,192,192)         && Cambiar el color de fondo a gris
    .BorderStyle=3                      && Cambiar el borde a doble
    .AutoCenter=.T.
    .WindowState=2
    ss1=sysmetric(1)
    ss2=sysmetric(2)
    DO CASE
       CASE ss1=800 and ss2=600
            .Picture=sys(5)+curdir()+"imagenes\COLSERVICE\imagen principal800.gif"
       CASE ss1=1024 and ss2=768>
            .Picture=sys(5)+curdir()+"imagenes\COLSERVICE\imagen principal1024.gif"
       CASE ss1=1152 and ss2=864
            .Picture=sys(5)+curdir()+"imagenes\COLSERVICE\imagen principal1152.gif"
    ENDCASE
   .Minbutton=.T.
   .Autocenter = .T.
   .Caption="HELP DESK 2000"            && Establecer un título
   .LockScreen=.F.                     && Activa el redibujado de pantalla
ENDWITH