.net - Using SortCompare Event To Sort Datagridview Integer-wise?

I use the streamreader to fill a datagridview. I need to sort the datagridview integer-wise and have tried to use the SortCompare event. To compare the row values i use the function

Public Function CompareIntegers(ByVal value1 As String, ByVal value2 As String) As Integer
Dim int1 As Integer = Integer.Parse(value1)
Dim int2 As Integer = Integer.Parse(value2)

[code]....

Which i call from the SortCompare event with

Private Sub DGV_SortCompare(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewSortCompareEventArgs)
e.SortResult = CompareIntegers(e.CellValue1, e.CellValue2)
End Sub

The event is fired but the datagridview is still sorted as strings.