Visual Basic.NET - ayuda conmi datagriw update

Hola:
mira tengo un drama cuando quiero actualizar mi dataset:

Dim rut, ext, fon As Integer
Dim nom, ape, car As String

rut = Me.DataGridView1.CurrentRow.Cells.Item(0).Value
nom = Me.DataGridView1.CurrentRow.Cells.Item(1).Value
ape = Me.DataGridView1.CurrentRow.Cells.Item(2).Value
car = Me.DataGridView1.CurrentRow.Cells.Item(3).Value
ext = Me.DataGridView1.CurrentRow.Cells.Item(4).Value
fon = Me.DataGridView1.CurrentRow.Cells.Item(5).Value
Dim conexion As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Documents and Settings\Hector Manuel Soria\Mis documentos\pruenet\basenet.mdb")
Dim miAdaptar As New OleDbDataAdapter("update Empleados set Nombre = '" & nom & "', Apellidos = '" & ape & "' where id_nombre = '" & rut & "' ", conexion)


Dim dataset1 As New System.Data.DataSet
miAdaptar.Update(dataset1)


DataGridView1.DataSource = dataset1.Tables(0)
DataGridView1.Refresh()