acceptchanges does not work on my datagrid/dataset

[paulhudson]

I have a datgrid bound to a dataset. I am using dataset.acceptchanges() to update the edited parts of the datagrid - but it fails to do this.

The OnEditCommand works fine, OnUpdateCommand simply returns datagrid exactly as it was prior to edit.

The code is:

Sub DoItemUpdate(ByVal sender As Object, ByVal e As DataGridCommandEventArgs)
Dim tpDataSet As New DataSet()
tpDataSet = Session("tpDataSet")
tpDataSet.AcceptChanges()
dgr1.DataSource = tpDataSet.Tables("TeamPlayers")
dgr1.DataBind()
End Sub

Any help would be gratefully appreciated.