AddNew overwrites existing record

I have a windows form that uses a listbox to navigate through a table in a database. The interface is meant to view, edit record, delete record, add record, and update the table in the database.

Whenever I input data and click add, the data overwrites whatever entry is presently selected in the listbox. This is despite changing the data for the primary key.

The other buttons work fine.

This is the code for the add button:

VB Code:

Private Sub btnAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAdd.Click
        Try
            'Clear out the current edits
            Me.BindingContext(objDSPatients, "Biodata").EndCurrentEdit()
            Me.BindingContext(objDSPatients, "Biodata").AddNew()
        Catch eEndEdit As System.Exception
            System.Windows.Forms.MessageBox.Show(eEndEdit.Message)
        End Try
        Me.objDSPatients_PositionChanged()
    End Sub

This is the code for the listbox:

VB Code:

Private Sub ListBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListBox1.SelectedIndexChanged
        Try
            Me.BindingContext(objDSPatients, "Biodata").Position = ListBox1.SelectedIndex
        Catch dataException As Exception
            MsgBox(dataException.Message)
            Me.BindingContext(objDSPatients, "Biodata").CancelCurrentEdit()
            Me.BindingContext(objDSPatients, "Biodata").Position = ListBox1.SelectedIndex
        End Try
    End Sub

This is the code relating the the dataset and all that:

VB Code:

Public Sub UpdateDataSet()
        'Create a new dataset to hold the changes that have been made to the main dataset.
        Dim objDataSetChanges As Health1.DSPatients = New Health1.DSPatients
        'Stop any current edits.
        Me.BindingContext(objDSPatients, "Biodata").EndCurrentEdit()
        'Get the changes that have been made to the main dataset.
        objDataSetChanges = CType(objDSPatients.GetChanges, Health1.DSPatients)
        'Check to see if any changes have been made.
        If (Not (objDataSetChanges) Is Nothing) Then
            Try
                'There are changes that need to be made, so attempt to update the datasource by
                'calling the update method and passing the dataset and any parameters.
                Me.UpdateDataSource(objDataSetChanges)
                objDSPatients.Merge(objDataSetChanges)
                objDSPatients.AcceptChanges()
            Catch eUpdate As System.Exception
                'Add your error handling code here.
                Throw eUpdate
            End Try
            'Add your code to check the returned dataset for any errors that may have been
            'pushed into the row object's error.
        End If
 
    End Sub
    Public Sub LoadDataSet()
        'Create a new dataset to hold the records returned from the call to FillDataSet.
        'A temporary dataset is used because filling the existing dataset would
        'require the databindings to be rebound.
        Dim objDataSetTemp As Health1.DSPatients
        objDataSetTemp = New Health1.DSPatients
        Try
            'Attempt to fill the temporary dataset.
            Me.FillDataSet(objDataSetTemp)
        Catch eFillDataSet As System.Exception
            'Add your error handling code here.
            Throw eFillDataSet
        End Try
        Try
            'Empty the old records from the dataset.
            objDSPatients.Clear()
            'Merge the records into the main dataset.
            objDSPatients.Merge(objDataSetTemp)
        Catch eLoadMerge As System.Exception
            'Add your error handling code here.
            Throw eLoadMerge
        End Try
 
    End Sub
    Public Sub UpdateDataSource(ByVal ChangedRows As Health1.DSPatients)
        Try
            'The data source only needs to be updated if there are changes pending.
            If (Not (ChangedRows) Is Nothing) Then
                'Open the connection.
                Me.OleDbConnection1.Open()
                'Attempt to update the data source.
                OleDbDataAdapter1.Update(ChangedRows)
                OleDbDataAdapter2.Update(ChangedRows)
                OleDbDataAdapter3.Update(ChangedRows)
                OleDbDataAdapter4.Update(ChangedRows)
            End If
        Catch updateException As System.Exception
            'Add your error handling code here.
            Throw updateException
        Finally
            'Close the connection whether or not the exception was thrown.
            Me.OleDbConnection1.Close()
        End Try
 
    End Sub
    Public Sub FillDataSet(ByVal dataSet As Health1.DSPatients)
        'Turn off constraint checking before the dataset is filled.
        'This allows the adapters to fill the dataset without concern
        'for dependencies between the tables.
        dataSet.EnforceConstraints = False
        Try
            'Open the connection.
            Me.OleDbConnection1.Open()
            'Attempt to fill the dataset through the OleDbDataAdapter1.
            Me.OleDbDataAdapter1.Fill(dataSet)
            Me.OleDbDataAdapter2.Fill(dataSet)
            Me.OleDbDataAdapter3.Fill(dataSet)
            Me.OleDbDataAdapter4.Fill(dataSet)
        Catch fillException As System.Exception
            'Add your error handling code here.
            Throw fillException
        Finally
            'Turn constraint checking back on.
            dataSet.EnforceConstraints = True
            'Close the connection whether or not the exception was thrown.
            Me.OleDbConnection1.Close()
        End Try
    End Sub