In VB.Net 2010 find.execute against Word 2007 document Gets Error 4605

Question

I am using VB.Net 2010 to use range.find.execute(sFindWord) to find words in Word 2007 documents and get error 4605 "This command is not available." I go through a loop doing the find on 38 documents. It works fine on all but three of the documents. They must not be protected, because my program can open them without userid & password. (When I have searched on Google for information on this error, some say the problem is that the document is protected.) One thing the documents which get the error have in common is that they have embedded attachments - email messages and Word documents. When I click on the attachment, I am taken to the top of the document I am in. On the other hand, I can open such attachments in one of the other documents.

Is there a way to open and do search in those documents?

[code]

    Dim WordApp As New Word.Application
    Dim docOpenedDocument As Microsoft.Office.Interop.Word.Document
    Dim wrdRange As Word.Range
    Dim iWordParagraph As Integer

        WordApp.Visible = False
        docOpenedDocument = WordApp.Documents.Open(ChangeToSharedPath(gsDatabaseNames(iThisDatabase)), _
                                                   objMissing, True)

        lblProgress.Text = "Searching: " & StrConv(gsDatabaseTypesFound(iThisDatabase), VbStrConv.ProperCase) _
            & " Database (" & iNumDatabasesSearched.ToString _
            & " of " & iNumDatabasesSearching.ToString & ")   " & _
            Path.GetFileNameWithoutExtension(gsDatabaseNames(iThisDatabase))
        frmGridDisplay.lblSearchProgressGridForm.Text = lblProgress.Text
        Application.DoEvents()

        iSearchHit = 0
        For iWordParagraph = 1 To docOpenedDocument.Paragraphs.Count

            If gbExitingGridForm Then
                'MessageBox.Show("Grid form closed unexpectedly - ending search", "Ending Search")
                Exit Sub
            End If

            wrdRange = docOpenedDocument.Paragraphs(iWordParagraph).Range

            wrdRange.Find.ClearFormatting()

            If Not bUsingAdvancedSearch Then

Error here -> If wrdRange.Find.Execute(sSearchPhrase.ToString) Then iSearchHit = 1 Exit For End If Else [/code]