Windows 2000 关闭/注销时，应用程序无法终止。

这是 MIDAS 三层中的客户端应用程序。
点 Button1,再点 Button2，或先 Button2,再 Button1 后，Windows 关闭/注销时，此程序不能终止。
服务端程序启动或不启动都无所谓，结果都一样。

高手快来帮忙啊。

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, DB, DBClient, MConnect, SConnect;

type
TForm1 = class(TForm)
Button1: TButton;
SocketConnection1: TSocketConnection;
Button2: TButton;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
try
SocketConnection1.Open;
except
SocketConnection1.Close;
end;
// Application.MessageBox('ddd','ddd');
// MessageBox(Handle,'aaa','ddd',0);
// showmessage('ok');
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
// Application.MessageBox('ddd','ddd');
// MessageBox(Handle,'aaa','ddd',0);
showmessage('ok');
end;

end.