{...}
type
  TForm1 = class(TForm)
    StringGrid1: TStringGrid;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    {...}
  public
    {...}
  end;
//from http://www.sharejs.com
type
  TStringGridHack = class(TStringGrid)
  protected
    procedure DeleteRow(ARow: Longint); reintroduce;
    procedure InsertRow(ARow: Longint);
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

procedure TStringGridHack.DeleteRow(ARow: Longint);
var
  GemRow: Integer;
begin
  GemRow := Row;
  if RowCount  FixedRows + 1 then
    inherited DeleteRow(ARow)
  else
    Rows[ARow].Clear;
  if GemRow then Row := GemRow;
end;

procedure TStringGridHack.InsertRow(ARow: Longint);
var
  GemRow: Integer;
begin
  GemRow := Row;
  while ARow do Inc(ARow);
  RowCount := RowCount + 1;
  MoveRow(RowCount - 1, ARow);
  Row := GemRow;
  Rows[Row].Clear;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  // Insert Row, Zeile hinzufügen
  TStringGridHack(StringGrid1).InsertRow(1);
  // Remove Row, Zeile entfernen
  TStringGridHack(StringGrid1).DeleteRow(2);
end;

end.
//delphi/8760