The tab and the wall work in different ways. The tab gets it's contents from our database, so if your posts show up on the tab then you know that you've registered your blog correctly. Congratulations. 

The wall, on the other hand, is like a stream of news. We publish posts to it and and Facebook distributes them to your fans. We call that feature "syndication". We only publish new posts to the wall, not old ones. In other words, only articles that you write 'after' you setup syndication are published to your wall. You can manage the syndication feature from the syndication page:

http://www.networkedblogs.com/syndication

Summary of differences between tab and wall:

- Tab shows your last 10 posts, even if they were written before you added the tab. The wall only shows new posts that you write after you stup syndication.

- Posts published to the wall get distributed to your fans home pages, but posts on the tab are only visible to your fans when they visit your fan page and click on the "Blog" tab. 

- If posts show up on your tab but not on the wall, then you probably didn't setup syndication or it's not working for some reason. You can check the syndication page (linked above), and read the syndication questions on this forum. 

http://help.networkedblogs.com/forums/323876-syndication