Ergebnis von CompareDateTime wird nie erreicht?

[Bummi]

Delphi-Quellcode:

uses DateUtils,Math;
{$R *.dfm}

procedure TForm4.Button1Click(Sender: TObject);
var
 d1,d2:TdateTime;
begin
   d1 := EncodeDateTime(2012,12,19,12,11,10,0);
   d2 := EncodeDateTime(2012,12,19,12,11,10,1);

   if CompareDateTime(d1,d2) = 0 then
      begin
        Showmessage('Same');
      end else Showmessage('Not Same');

    d1 := RoundTo(d1,-6);
    d2 := RoundTo(d1,-6);
   if CompareDateTime(d1,d2) = 0 then
      begin
        Showmessage('Same ' + DateTimeToStr(d1)+' - '+DateTimeToStr(d2));
      end else Showmessage('Not Same');

end;