Keine Grafikausgabe mit Image1.Canvas.MoveTo... unter Win 7

[Luckie]

Zeichnet wunderbar:

Delphi-Quellcode:

procedure TForm1.btn1Click(Sender: TObject);
begin
Image1.Canvas.Brush.Style := bsClear;
  Image1.Canvas.MoveTo(50,10);
  Image1.Canvas.LineTo(50,266);
  Image1.Canvas.LineTo(770,266);

 // Daten an rechten Rand schreiben
  Image1.Canvas.Pen.Color := clBlack;
  Image1.Canvas.MoveTo(790,10);
  Image1.Canvas.LineTo(790,266);
  Image1.Canvas.LineTo(930,266);
  Image1.Canvas.LineTo(930,10);
  Image1.Canvas.LineTo(790,10);
  Image1.Canvas.Pen.Color := clBlack;


  Image1.Canvas.Font.Style:=[];

end;