COM exception while selecting cells in excel with c#

I have a problem selecting a cell in excel using c# while running through a "for" loop.

I have 3 datatables in a dataset(dsReportGrid) which I'm exporting to excel (one sheet per table). When I try to select a range so I can freeze panes, it goes well in the first iteration of the loop (dsReportGrid.table[0]), but when it gets to second iteration when I try to select the cell in the secondsheet it throws me a COM exception on the select event (the code line with two asterisks).

Why is it happening and how can I handle it?

Thanks,

    private void saveXlS()
    {
        Excel.Application xlApp;
        Excel.Workbook xlWorkBook;
        Excel.Worksheet xlWorkSheet;
        Excel.Range xlCells;
        Excel.Range freezeCell;
        object misValue = System.Reflection.Missing.Value;

        xlApp = new Excel.ApplicationClass();
        xlWorkBook = xlApp.Workbooks.Add(misValue);

        for (int table = 0; table <= dsReportGrid.Tables.Count -1; table++)
        {

            xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(table +1);
               Excel.Range k = xlWorkSheet.get_Range("a2");
               **k.Select();**
               k.Application.ActiveWindow.FreezePanes = true;
               break;
        }
        ...rest of code writing from dataset to excel
   }开发者_StackOverflow中文版

Try activating the worksheet before attempting to select the range. I think you can only select a range on an active worksheet.