CKEditor not capturing data from ASP.NET textbox after postback

My CKEditor control is displayed. However, when I click save and the page posts back, I cannot get the new text from the control. See below where I've tried to retrieve the value. No matter what I do, I'm getting the old value.

I DON'T want to use the CKEditor ASP.NET control as it uses an old version of CKEditor that has some very annoying bugs.

<script type="text/javascript" src="/ckeditor/ckeditor.js"></script>
<script src="/ckeditor/adapters/jquery.js"></script>
<script type="text/javascript">
    $(function () {
        $('.ckeditor').ckeditor(function () { }, { toolbar: 'Editprofile' });
    });
</script>

<asp:TextBox ID="tbDescription_en" CssClass="ckeditor" TextMode="MultiLine" runat="server" />

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
    If Not Page.IsPostBack Then
        'tbDescription_en.Text is equal to old value here
    Else
        'tbDescription_en.Text is equal to old value here
    End If
End Sub

 Protected Sub lbSave_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles lbSave.Click
   'tbDescription_en.Text is equal to old value here
 End Sub