Datagridview dropdownbox value changed

[Danny M]

When i change the value in the dropdownbox.
The value changes.
When i check the datatable the value has changed
But when i want to save it to the database the record didnt got a
changed flag
When i do dtTest = dtData.getchanges then dtTest is nothing ???
But still the value in the datatable has the right value, but because
it didnt have a change flag it isnt saved to the database???

What i am doing wrong??

With _ColumnPositie
.HeaderText = "Positie"
.Width = 120
.DataSource = g_cDatabase.dtPositie
.DataPropertyName = "PlayerPositie"
.DisplayMember = "PositieOmschrijving"
.ValueMember = "Positie"
.Name = "cboPositie"
End With
dgvPlayers.Columns.Insert(3, _ColumnPositie)
mine update functie

Public Sub DBUpdate(ByVal dtData As DataTable, ByVal sTabelNaam As
String)

Dim daUpdate As New SqlDataAdapter()
daUpdate.SelectCommand = New SqlCommand("Select * from " &
sTabelNaam, _SQLConn)
Dim cbUpdate As SqlCommandBuilder = New
SqlCommandBuilder(daUpdate)

Dim dtTest As DataTable
dtTest = dtData.GetChanges

cbUpdate.GetDeleteCommand()
cbUpdate.GetInsertCommand()
cbUpdate.GetUpdateCommand()

daUpdate.Update(dtData)
dtData.AcceptChanges()
End Sub

and if a value changes:

Private Sub dgvPlayers_CellValueChanged(ByVal sender As Object, ByVal e
As System.Windows.Forms.DataGridViewCellEventArgs) Handles
dgvPlayers.CellValueChanged

If dgvPlayers.CurrentCell.ColumnIndex = 3 Then
g_cDatabase.DBUpdate(dgvPlayers.DataSource, "T_Players")
End If
end sub