FQL friends photos - empty

Hey... I try to get my friend's photos.

FB login button code:

<开发者_运维百科fb:login-button show-faces="true" width="200" max-rows="1" perms="user_photos,friends_photos,user_photo_video_tags,friends_photo_video_tags"></fb:login-button>

FQL query (uid is user ID):

SELECT pid, aid, owner, src, src_small, created FROM photo WHERE aid IN (SELECT aid FROM album WHERE owner="+uid+") ORDER BY created DESC LIMIT 30

Why in some cases I get no photos? If I see my friend's profile I can see he has 100+ photos but the request is saying no. I would like to get 10 random images for friend with uid=X.

Thanks for tips.enter code here