I thought I would post an update;
It is working now - Seems a limitation exist in the DNN Article provider (maybe). If you do not have a sub-category metapost will not post the article. It appears to works but after you check for the posting it is not there.
Example Category: World Conflict (single category - will not work)
Example Category with sub node;
World Conflict
.....Russia (check both categories in live writer and meta post will post the article)
Solution; Add a subcategory to the DNNArticle and ensure you tick them both in livewriter.