Entity update failed
===

Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries.

I just started learning entity and have done some playing with it in Winforms and now with Webforms. It was working fine for a few days and now I get the error when I try to update a field in the DataView. 'AutoGenerateEditButton="True" in the DV. The DV is wired to the EntityDataSource. A friend accessed the webform and edited one from a diff location and was the last time the edit/update worked. 

This is the updating event in case that helps:

    Sub dgv_RowUpdating(ByVal sender As Object, ByVal e As GridViewUpdateEventArgs) Handles dgv.RowUpdating
    Try
      Dim row As GridViewRow = dgv.Rows(dgv.EditIndex)
      Dim list As DropDownList = CType(row.FindControl("ddlDoseType"), DropDownList)
      e.NewValues("DoseType") = list.SelectedValue
    Catch ex As Exception
      MsgBox(ex.ToString)
    End Try
    End Sub

Any ideas? 