I also had a problem with a GridView that was not updating. Inspection of the e.Newvalues Dictionary in the GridView's RowUpdating event showed that the old values for the record were being sent to the database UPDATE query. DataKeyNames was not my problem; I had it set correctly. The WHERE clause of my SELECT query referenced a control parameter against a TextBox on my form. I had inadvertently set EnableViewState for this textbox to "False"....