InfoPath Dev

Sub PopulateRepeatingTable(ByVal DataSource As String, ByVal SourceXPath As String, ByVal SourceFields() As String, _
                                   ByVal DestXPath As String, ByVal DestTable As String, ByVal DestFields() As String, Optional ByVal Nested As String = "")

            Dim NodeIterator As XPathNodeIterator = DataSources(DataSource).CreateNavigator().Select(SourceXPath, NamespaceManager)
            Dim Field As String

            For Each Node As XPathNavigator In NodeIterator

                Dim MyNamespace As String = NamespaceManager.LookupNamespace("my")

                If Node Is Nothing Then
                    'Do Nothing
                Else
                    Using Writer As XmlWriter = MainDataSource.CreateNavigator().SelectSingleNode(DestXPath, NamespaceManager).AppendChild()

                        Writer.WriteStartElement(DestTable, MyNamespace)

                        Dim i As Integer = 0

                        For Each Field In SourceFields

                            If Node.SelectSingleNode(SourceFields(i)) Is Nothing Then
                                Writer.WriteElementString(DestFields(i), MyNamespace, "")
                            Else
                                Writer.WriteElementString(DestFields(i), MyNamespace, Node.SelectSingleNode(SourceFields(i)).ToString)
                            End If
                            i = i + 1

                        Next

                        Writer.WriteEndElement()
                        Writer.Close()

                    End Using

                End If

            Next

        End Sub

Repeater XPath:
"/my:ProgrammeForm/my:Structure/my:CoreStream/my:ElectiveBundlesSectionGroup/my:ElectiveBundlesSection" (Yes, the repeater is called ElectiveBundlesSection. I must rename to something a bit better)

Nested Repeater XPath:
"my:ProgrammeForm/my:Structure/my:CoreStream/my:ElectiveBundlesSectionGroup/my:ElectiveBundlesSection/my:ElectiveBundlesGroup/my:ElectiveBundles"

I keep running in to a NullException... Whichever repeater I populate first, populates successfully e.g. I can call the function to populate the nested repeater but if i call the function again to populate the parent, a Null Exception is encountered. Same thing happens in reverse.

The XmlWriter appears to be creating only certain fields for a node and then when I try to populate either nested fields or parent fields of that node, it can't seem to find them. I don't really understand how it works so here I am! :)

This is a project for work and i need to have it sorted out asap. I'd really appreciate advice on this.

Thanks a million,

Ben