IE sorting problem?

This code creates a table with 2 columns. In Firefox, I can click on either column header and the sort works correctly. But in IE6 I can't sort either column.

If I reduce the column count from 8 to 4, then the sorting works OK in IE. Similar code works OK in AW 1.0, in FF and IE.

Any ideas?

var obj = new AW.UI.Grid;

rowdata = [
    [88.7, 36],
    [30.4, 25],
    [72.7, 60],
    [56.0, 86],
    [30.4, 23],
    [51.0, 34],
    [70.6, 60],
    [52.2, 21],
];
obj.setRowCount(8);
obj.setColumnCount(2);
obj.setCellText(function(col,row){
     return "value[" + row + "," + col + "]=" + rowdata[row][col];});
obj.setCellValue(function(col,row){return rowdata[row][col];});
document.write(obj);

Sorry, never mind, I see now that with 2.0 I need this:

var number = new AW.Formats.Number;
obj.setCellFormat(number, 0); 
obj.setCellFormat(number, 1);

But now I'm wondering why do I need to call setCellFormat?

Since I specify the array of unformatted cell values in setCellValue(), shouldn't those values be used to sort each column?