title: Postgres zipcode - listings for same mile radius not showing up
body: <p>Using Postgres and extensions <code>cube</code> and <code>earthdistance</code> I do this query for zipcode 78705 with 50 miles radius range:</p>
  
  <pre><code>  WITH query1 AS(SELECT * FROM listings
      WHERE earth_box(ll_to_earth(30.2961708, -97.73895429999999), 80467.2)
      @&gt; ll_to_earth(listings.lat, listings.lng)
  </code></pre>
  
  <p>and I get back result foo listing, which is great. </p>
  
  <p>If I do a query for zipcode 78232 with a 50 miles radius range:</p>
  
  <pre><code> WITH query1 AS(SELECT * FROM listings
      WHERE earth_box(ll_to_earth(29.59442259999999, -98.4568128), 80467.2)
      @&gt; ll_to_earth(listings.lat, listings.lng)
  </code></pre>
  
  <p>I get back the expected results, including the listing foo. </p>
  
  <p>My question is.... if foo(which is zipcode 78705) is returned for a 50 mile radius of 78232 with other listings that are 78232, why aren't all the listings from zipcode 78232 being included in a 50 mile radius of 78705?</p>