Threading trouble

Private Delegate Sub LoadGridDelegate()
Private Delegate Sub ClearGridDelegate()
Private Delegate Sub AddGridRowDelegate(ByVal r As DataGridViewRow)
 
Private Sub ClearGrid()
        If Me.OpenInvoicesGrid.InvokeRequired Then
            Dim usd As New ClearGridDelegate(AddressOf ClearGrid)
            Me.Invoke(usd, New Object() {})
        Else
            Me.OpenInvoicesGrid.Rows.Clear()
        End If
End Sub
 
Private Sub AddRow(ByVal r As DataGridViewRow)
        If Me.OpenInvoicesGrid.InvokeRequired Then
            Dim usd As New AddGridRowDelegate(AddressOf AddRow)
            Me.Invoke(usd, New Object() {r})
        Else
            Me.OpenInvoicesGrid.Rows.Add(r)
        End If
End Sub
 
Private Sub LoadGrid()
     ClearGrid()
     for i as integer = 0 to 10
          'calculation code here to create a DGV row
          ' r is a DataGridViewRow that contains info that i've calculated
          AddRow(r)
     next
End Sub
 
Public Sub LoadOpenInvoicesGrid()
        finished = False
        LoadThread = New System.Threading.Thread(AddressOf LoadGrid)
        LoadThread.Priority = Threading.ThreadPriority.Highest
        LoadThread.IsBackground = True
        LoadThread.Start()
        While Not finished
            System.Windows.Forms.Application.DoEvents()
        End While
End Sub