Just for others who encountered the same problem like me, I am sharing with you my finding. My problem was that when I paged through the follower-list of a user (myself for example), I found that that the resulting followers count are less than what it is stated in the user/show result. If I count the list of followers from the social-graph, it will yield the same number as the user/show. So there is some discrepancy between the two result (in my case it was more than 200 odds).
So, I manually pulled the remaining followers who were not on the paged list but were in the social-graph, and what I found was that each of this account was 'suspended'. This led me to conclusion that maybe that was the reason why they were not on the paged list, the API can't possibly bring back a suspended account. HTH, Chris Prakoso