title: Exporting system.profile from MongoDB doesn't work
body: <p>I am trying to do export:</p>
  
  <pre><code>ilya@server ~]$ mongoexport --host localhost --port 27000  --collection system.users --db mydb --out profile.json                
  connected to: localhost:27000
  exported 1 records
  </code></pre>
  
  <p>Works ok with <code>system.users</code></p>
  
  <p>But doesn't work with <code>system.profile</code>:</p>
  
  <pre><code>[ilya@server ~]$ mongoexport --host localhost --port 27000  --collection system.profile --db mydb --out profile.json
  connected to: localhost:27000
  exported 0 records
  </code></pre>
  
  <p>Collection is not empty:</p>
  
  <pre><code>[ilya@server ~]$ mongo localhost:27000/mydb
  MongoDB shell version: 2.2.3
  connecting to: localhost:27000/mydb
  mongos&gt; db.system.profile.count();
  1044
  </code></pre>
  
  <p>I need these rows to export and work with them somewhere, for example as with normal collection(not capped as <code>system.profile</code>).</p>