换office2007后导出EXCEL出错

代码将Stringgrid导出成Excel,在office2003时没有问题，但今天换成2007后，提示格式太旧，没法导出数据。具体代码如下
var
  ASheet:Variant;
  i,j:integer;
begin
  ExcelApplication1.Visible[0]:=True;
  ExcelApplication1.WorkBooks.Add(xlWBATWorksheet,1);
  ASheet:=ExcelApplication1.Worksheets.Item[1];
  for i:=0 to StringGrid1.RowCount-1 do
  for j:= 0 to StringGrid1.ColCount-1 do
  ASheet.cells[i+1,j+1].Value:=StringGrid1.Cells[j,i];
end;