Cant append one specific document

I wrote a program that takes documents and appends them to a new document. THis works fine until i try to append the table of contents document. It doesnt seem to append that document. Here is a snippet of my code. Every other document works fine ( so it seems)

If Section159.Checked = True Then

Dim srcdoc159 As Document = New Document("c:/inetpub/wwwroot/intranet9/trusts/data/section159.doc")

Dim section159 As Section = srcdoc159.Sections(0)

dstdoc.Sections(dstdoc.Sections.Count - 1).AppendContent(section159)

End If

If Section160.Checked = True Then

Dim srcdoctoc As Document = New Document("c:/inetpub/wwwroot/intranet9/trusts/data/sectiontoc.doc")

Dim sectiontoc As Section = srcdoctoc.Sections(0)

dstdoc.Sections(dstdoc.Sections.Count - 1).AppendContent(sectiontoc)

End If

dstdoc.Save("C:\inetpub\wwwroot\intranet9\trusts\output\" & outputname.Text & ".doc")

Please attach several of your documents illustrating the problem. I will try to find out what the problem is.