Questa è il mio form, ho modificato come mi hai suggerito tu, (ho provato a richiamare LoadData() prima del catch, ma mi dice che fa riferimento ad un oggetto nn impostato su un'istanza di oggetto)... Devo "costruire" la mia form in modo diverso?

Grazie 1000 x l'aiuto.
Ciao

Imports System.Data
Imports System.Data.OleDb

Public Class ArticoliPage

' Percorso del DataBase (db.mdb)
Dim PercorsoDB As String = "C:\db.mdb"

' Stringa di Connessione
Dim objConnection As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; " & "Data Source=" & PercorsoDB)
Dim objDataAdapter As New OleDbDataAdapter()
Dim objDataSet As New DataSet()


Private Sub ArticoliPage_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
LoadData()
End Sub

Private Sub LoadData()
objDataAdapter.SelectCommand = New OleDbCommand()
objDataAdapter.SelectCommand.Connection = objConnection
objDataAdapter.SelectCommand.CommandText = "Select * from Articoli"
objDataAdapter.SelectCommand.CommandType = CommandType.Text

' Open db connction
objConnection.Open()

' Fill
objDataAdapter.Fill(objDataSet, "Articoli")

' Close db connection
objConnection.Close()

' Set datagridview properties
DataGridView1.AutoGenerateColumns = True
DataGridView1.DataSource = objDataSet
DataGridView1.DataMember = "Articoli"

' Change Column Name anfd width
DataGridView1.Columns(0).Visible = False
DataGridView1.Columns(1).HeaderText = "Codice"
DataGridView1.Columns(1).Width = 150
DataGridView1.Columns(2).HeaderText = "Descrizione"
DataGridView1.Columns(2).Width = 250
' Clean up
objDataAdapter = Nothing
objDataAdapter = Nothing
End Sub

Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click

Dim objCommand As OleDbCommand = New OleDbCommand()
objCommand.Connection = objConnection

objCommand.CommandText = "insert into Articoli" & _
"(articolo,descrizione,prezzo,misura) " & _
"values(articolo, descrizione, prezzo, misura);"

' Set Variables
objCommand.Parameters.AddWithValue("articolo", TBCodice.Text)
objCommand.Parameters.AddWithValue("descrizione", TBDescrizione.Text)
objCommand.Parameters.AddWithValue("prezzo", TBPrezzo.Text)
objCommand.Parameters.AddWithValue("misura", TBMisura.Text)

' Open Conn
objConnection.Open()

' Execute Command
Try
objCommand.ExecuteNonQuery()
MessageBox.Show("Inserimento eseguito con successo")

Catch ex As Exception
MessageBox.Show(ex.Message)
End Try

' Close Conn
objConnection.Close()
End Sub

End Class