I'm using the api to retrieve friends and followers for a popular user but it seems the api and the twitter friends and followers webpage end the listing quite early in the listing. (I'm assuming the webpages just use the api behind the scenes)
For example check out stephenfry's profile... He's got 316888 followers which should result in over 15000 pages of followers (20 per page). However if you go to, say, page 1000 there are no results: http://twitter.com/stephenfry/followers?page=1000 (the listing actually ends on page 647: http://twitter.com/stephenfry/followers?page=647) I'm seeing the exact same issue with my client. The api also stops the listing early. Anyone able to shed any light?