title: iphone app NSNumber memory leak
body: <p>I'm having a memory leak and I have no clue where it comes from and how to fix it.</p>
  
  <p>At some point i calculate the distance between 2 locations.</p>
  
  <pre><code>double calc = [self getDistance:location to:otherLocation];
  NSNumber *distance = [NSNumber numberWithDouble:calc];
  </code></pre>
  
  <p>in instruments i get as leaked object NSCFNumber and it identifies </p>
  
  <pre><code>NSNumber *distance = [NSNumber numberWithDouble:calc];
  </code></pre>
  
  <p>as the line causing this.</p>
  
  <p>I'm at a loss. Please help.</p>
  
  <p>thanks in advance,
  Michiel</p>