Word - This Object does not Support Attached Text

Question

Hi,
Hope this is the right place for the post. I am getting an error: This Object does not support attached text.  This is generated working with Word9 with .NET 1.1.  Worked fine on XP with word 9 and 11, but word 2007 on vista is throwing this error when populating a text box.  Below in the code. Does anyone know a work around?  Thanks.

object tb9 = "Text Box 9";
            objWord.ActiveDocument.Shapes.Range(ref tb1).Select(ref M);
            objWord.Selection.ShapeRange.TextFrame.TextRange.Text = m_PermNo;