title: Pymongo returning incorrectly when using "$gte" and "$lte"
body: <p>I'm attempting to select from mongo (using pymongo), querying against epoch timestamps. 
  A sample from my database is (pruned for brevity):</p>
  
  <pre><code>{
      "_id": "",
      "tweet": {
          "iso_language_code": "en",
          "to_user_name": null,
          "timestamp": 1355325948,
          "created_at": "Wed, 12 Dec 2012 15:25:48 +0000"
      }
  }
  </code></pre>
  
  <p>And the query, in code and within python console:</p>
  
  <pre><code>&lt;console&gt;
  db.tweets.find({
      "tweet.timestamp":{'$gte':1355391000},
      "tweet.timestamp":{'$lte':1355414400}
  })
  
  &lt;code&gt;
  cursor = db.tweets.find({"tweet.timestamp":{'$gte':startEpoch},
                           "tweet.timestamp":{'$lte':endEpoch}})
  </code></pre>
  
  <p>Which are  <em>Thu, 13 Dec 2012 09:30:00 GMT</em> and <em>Thu, 13 Dec 2012 16:00:00 GMT</em> respectively. </p>
  
  <p>It should be saying, get me all tweets <em>gte this int</em> and <em>lte this other int</em>. However, it returns EVERYTHING - it doesn't seem to be limiting the values at all. </p>
  
  <p>For example, this entry is returned, and the timestamp is: <em>1355325948</em> which is: <em>Wed, 12 Dec 2012 15:25:48 GMT</em></p>
  
  <p>Also, my understanding that find(...) with a list of params is an implicit AND. </p>
  
  <p>TIA SO!</p>