Problem with GUI not updating in MDI

I have a MDI parent form (frmMain.vb). When I call a form(Import.vb) in it I cant get the interface to update. When I set the form (Import.vb) as the startup form it works just fine.

Here is the code im using:

FORM MAIN (frmMain.vb)
Imports System.Windows.Forms

Public Class frmMain
    Private Sub ImportToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ImportToolStripMenuItem.Click
        Dim frmChild As New Import
        frmChild.MdiParent = Me
        frmChild.Show()
    End Sub
End Class

FORM IMPORT (Import.vb)
Imports System.Configuration.ConfigurationSettings

Public Class Import
    Private excelObj As New Sys.Cap.Data.ExcelObj
    Private formImport As Import

    Private Sub btnImport_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnImport.Click
        excelObj.PopExcel(formImport)
    End Sub
End Class

EXCEL OBJ (ExcelObj.vb)
Namespace Sys.Cap.Data
    Public Class ExcelObj
        Private formImport As Import

        Public Sub PopExcel(ByRef frm As Import)
            formImport = Import
            formImport.Label1.Text = "TEST"
            formImport.Refresh()
            Exit Sub
        End Sub
    End Class
End Namespace

Any idea why the label updates properly when I set Import.VB as the startup form and doesnt update at all when I set the frmMain.VB as the startup form?