SAP com VB6 VB.NET Diferença de comportamento

Private Sub Form_Terminate()
    SAPBAPIControl.Connection.Logoff
End Sub

Private Sub SAPLogonControl_Click()
    Set SAPBAPIControl.Connection = SAPLogonControl.NewConnection
    SAPBAPIControl.Connection.Client = "100"
    If SAPBAPIControl.Connection.Logon(0, False) Then
        MsgBox SAPBAPIControl.Connection.IsConnected
    End If
End Sub

em VB.NET 2010 I write:

Public Class MainForm
    Private Sub MainForm_FormClosing(sender As Object, e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
    AxSAPBAPIControl1.Connection.Logoff()
End Sub

    Private Sub AxSAPLogonControl1_ClickEvent(sender As Object, e As System.EventArgs) Handles     AxSAPLogonControl1.ClickEvent
        AxSAPBAPIControl1.Connection = AxSAPLogonControl1.NewConnection()
        AxSAPBAPIControl1.Connection.Client = "100"
        If AxSAPBAPIControl1.Connection.Logon(0, False) Then
            MsgBox(AxSAPBAPIControl1.Connection.IsConnected)
        End If
    End Sub
End Class

e acabar com:

Eine Ausnahme (erste Chance) des Typs "System.AccessViolationException " ist in mscorlib.dll aufgetreten. em .Cliente = " 100 "