title: facebook post and page insights not working
body: <p>I'm using Graph API to get statistics from my pages , I created an application and I got my permissions (read_insights , manage_pages ...) , but only some metrics work fine like page_fans_country and most of them (page_fans / post_impressions / page_impressions / page_fans_gender_age ...) don't work and return : [data] => Array () .
  I tried 3 different pages , the first have 20.000 likes , the second 3.000 and the third 30 likes , and I can't get any information from them except for page_fans_country . But when I try those previous queries in Graph Api Explorer with its token , it works fine , when I use my token it doesn't work , and i'm sure i have the read_insights permission</p>
  
  <p>Please , Help me .</p>