Thanks for the quick reply. I was able to resolve the issue on my own. I misreported the issue. Upon closer inspection of the relevant code and additional testing I noted that the Document.AppendDocument was working as inspected. But, there was another component in the code that does an insertion after a paragraph node. It was the latter action that was causing the document to lose the orientation. I don't know exactly why it behaved that way. But, I'm happy to have the problem resolved :-)
