[Most Recent Entries]
There are a few reasons why you might not see posts on this friends page:
in_b might have no friends defined. If you are in_b, you can
edit your LiveJournal friends
so they show up here.
in_b might have friends defined, but all of their friend's posts might be over two weeks old (according to the times on our servers), and thus wouldn't be displayed here.
in_b might have friends defined that post only protected entries that you can't view, because they haven't defined you as a friend in return.