dnn设定了定制的注册页面转不过去

dnn4.5.3
转不过去，是由于dnn的问题，修改admin/skins/user.ascx.vb,

 Private Sub cmdRegister_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles cmdRegister.Click
            Try
                If Request.IsAuthenticated = False Then
                    If PortalSettings.UserRegistration <> PortalRegistrationType.NoRegistration Then
                        If URL <> "" Then
                            Response.Redirect(URL, True)
                        Else
                            Dim ReturnUrl As String = HttpContext.Current.Request.RawUrl
                            If ReturnUrl.IndexOf("?returnurl=") <> -1 Then
                                ReturnUrl = ReturnUrl.Substring(0, ReturnUrl.IndexOf("?returnurl="))
                            End If
                            ReturnUrl = HttpUtility.UrlEncode(ReturnUrl)

                            If PortalSettings.UserTabId <> -1 Then
                                ' user defined tab
                                Response.Redirect(NavigateURL(PortalSettings.UserTabId, "", "returnurl=" & ReturnUrl), True)