That's not an API question, unless I misunderstand. That's a page on
the main web site.
I don't actually know the answer to your question, as I didn't work
on that part of the site. I'm pretty sure that page is limited to
recent activity, for performance reasons. The idea is that each of
the friends' profiles offer their full history, so it's OK that it
isn't duplicated in the profiles of each of their fans.
Ugh. Bug. Fixed.
Which is to say: Please check the fix we just made live, and let me
know if you still see the problem.
Thanks for reporting it.