Yep, some things are probably privacy settings. I'm used to the LJ way... if you make something friends-only, and a friend comments on it, only your other friends can see the comment, not the friend's friends too.

Now I've figured out that only my wall/news-feed stops at 2 days ago. If I look directly on my friends' walls, it shows older posts.

Ah, and if I click the "Most Recent" link at the top of the page, then it puts the posts in order by date/time. The default "Top News" display puts them in an undefined order.

It's beginning to make more sense. :)