Only around 4000 US votes
When you click the number of votes
http://www.imdb.com/title/tt1187043/ratings?ref_=tt_ov_rt
You can see the voting details and currently it has:
Males 37641 8.1
Females 5654 8.1
US users 4146 7.3
Non-US users 39149 8.2
IMDb users 65325 8.3
Only 4146 US based users, so most others are Indian or Asian fan boys who desperately want to push this film into top 100 or smth.
Also the US users dont vote it as high as 8, so it wouldnt be in top.
Compare those numbers to say Pulp Fiction:
Males 475317 9.0
Females 76669 8.5
US users 166023 8.9
Non-US users 385963 9.0
IMDb users 740158 9.0