[NumLock]

а так пробовал:

Код:

procedure TForm1.Button1Click(Sender: TObject);
var
  MemoryStream: TMemoryStream;
begin
//  RichEdit1.PlainText:=False;
//  RichEdit2.PlainText:=False;
  MemoryStream:=TMemoryStream.Create;
  try
    RichEdit1.Lines.SaveToStream(MemoryStream);
    MemoryStream.Position:=0;
    RichEdit2.Lines.LoadFromStream(MemoryStream);
  finally
    MemoryStream.Free;
  end;
end;

?