title: FQL - Getting pid of the photos user is tagged in gives different results with different query
body: <p>I am trying to get the photos a user is tagged in. I am using the query:</p>
  
  <pre><code>SELECT pid 
  FROM photo 
  WHERE pid 
  IN (SELECT pid FROM photo_tag WHERE subject=me())
  </code></pre>
  
  <p>The number of results I get is 32. However when I run this query:</p>
  
  <pre><code>SELECT pid FROM photo_tag WHERE subject=me()
  </code></pre>
  
  <p>The number of results I get is 67. This is the number I expect because I am tagged in 67 pictures, not just 32. What am I doing wrong with the query?</p>