Save changes wont work??

[venerable bede]

I fill a dataset with the following:

'fiLLDATASET WITH INFO FROM DATAADAPTOR
objOwnerDA.Fill(objdataset, "tblItems")

The dataset is displayed 1 record at a time on a form with a button to save changes :

Private Sub btnSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click
objOwnerDA.Update(objdataset, "tblItems")
End Sub

The button doesnt save the changes.

Any Ideas???