[marcoszorrilla]

Prueba esto:

Código Delphi [-]
 
 type
   TForm1 = class(TForm)
     CheckBox1: TCheckBox;
     procedure CheckBox1Click(Sender: TObject);
     procedure FormActivate(Sender: TObject);
   private
     { Private declarations }
   public
   chkState:TCheckBoxState;
     { Public declarations }
   end;
 
 var
   Form1: TForm1;
 
 implementation
 
 {$R *.DFM}
 
 procedure TForm1.CheckBox1Click(Sender: TObject);
 begin
 Checkbox1.State:=chkState;
 end;
 
 procedure TForm1.FormActivate(Sender: TObject);
 begin
 chkState:=CheckBox1.State;
 end;

Un Saludo.