problemas con hilos (Thead)

[jmlifi]

no llega a ejecutarse esta parte del codigo:

Código Delphi [-]
procedure TThread5.Execute;
begin
 repeat
  Sleep(20000);
  Synchronize(RecepAutoVeriTubo);
  until terminated;
end;

la otra parte del código:

Código Delphi [-]
   TThread5 = class (TThread)
  private
      OwnerHandle: HWND;
      procedure RecepAutoVeriTubo;
  protected
      procedure Execute; override;
  published
      constructor Create(Owner: TForm);
      destructor Destroy; override;
  end;
.....
.....
 
Constructor TThread5.Create(Owner: TForm);
begin
  inherited Create(True);
  OwnerHandle := Owner.Handle;
  Priority := tpNormal;
  FreeOnTerminate := true;
  suspended := false;
end;

¿ a qué se debe ?